WO2023094901A1

WO2023094901A1 - The production process of optical nano sensors based on polymeric nanocomposite for rapid detection of small amounts of toxic ions, to be detected by the eye

Info

Publication number: WO2023094901A1
Application number: PCT/IB2022/057826
Authority: WO
Inventors: Roya SEDGHI; Bahareh HEIDARY; Pourya ZARSHENAS
Original assignee: Sedghi Roya; Heidary Bahareh; Zarshenas Pourya
Priority date: 2021-11-28
Filing date: 2022-08-21
Publication date: 2023-06-01

Abstract

The optical Nano sensor based on the UV-vis spectrum of polymeric nanocomposite in the presence of different concentrations of toxic ions and eye detection of heavy metal ions by the solution of mercury, cadmium, uranium, and copper ions with 100 ppb concentration. The intended research is the optical Nano sensor of heavy metal ions based on titanium oxide mineral material in Nano dimensions and polymeric composite containing hydrophilic groups. a chemical sensor, which is in fact an indicator and designator of the presence or absence of heavy metal ions in water and aquatic environments, is a gray powder that by being added to the intended water sample, while its color is changing to the customized color of each ion, is analyzed, simultaneously. This powder functions by being added in slight amounts to the water and stirred. Then, by waiting around 5 minutes, the change in the color would be observed.

Description

The production process of optical Nano sensors based on polymeric nanocomposite for rapid detection of small amounts of toxic ions, to be detected by the eye.

The process of producing the optical Nano sensor based on the UV-vis spectrum of polymeric nanocomposite in the presence of different concentrations of toxic ions and eye detection of heavy metal ions by the solution of mercury, cadmium, uranium, and copper ions with 100 ppb concentration. the intended research is the optical Nano sensor of heavy metal ions based on titanium oxide mineral material in Nano dimensions and polymeric composite containing hydrophilic groups. a chemical sensor, which is in fact an indicator and designator of the presence or absence of heavy metal ions in water and aquatic environments, is a gray powder that by being added to the intended water sample, while its color is changing to the customized color of each ion, is analyzed, simultaneously. this powder functions by being added in slight amounts to the water and stirred. Then, by waiting around 5 minutes, the change in the color would be observed.

A61B 5/00- B82Y 5/00- G01N 33/543

Other mentioned methods also have limitations in use despite high sensitivity and low detection limit due to being large, expensive and non-portable. Using a chemical sensor based on color change is very simple and the color change is the result of the specific interaction of the sensor with the ions in the water environment and it provides the type of target ions and its exact amount in the water environment in such a way that visual identification happens in a fraction of a second and accurate determination of the type and amount of ions does not require a special device and operator.

High sensitivity metamaterial Nano-sensing system with ultra-narrow line width spectral response

United States Patent 9841376

The invention relates to a metamaterial Nano-sensing system, and in particular to a high-sensitivity metamaterial Nano-sensing system with an ultra-narrow line width spectral response. The system includes an input light path, a metamaterial Nano-sensing unit and an output light path which are sequentially provided along a direction of a light path, and the metamaterial Nano-sensing unit includes a Bragg grating and a metallic periodic array arranged above the Bragg grating. The Nano-sensing system provided by the invention has an ultra-narrow line width spectral response, so that sensitivity of a Nano sensor is effectively improved, and broad application prospect in the fields of portable bio sensing, drug development and detection, environment monitoring and the like is ensured.

Apparatus and method for fabricating arrays of atomic scale contacts and gaps between electrodes and applications thereof

US7030452B2

A method for forming atomic scale contacts and atomic scale gaps between two electrodes is disclosed. The method provides for applying a voltage between two electrodes in a circuit with a resistor. The applied voltage etches metal ions off one electrode and deposits the metal ions onto the second electrode. The metal ions are deposited on the sharpest point of the second electrode, causing the second electrode to grow towards the first electrode until an atomic scale contact is formed. By increasing the magnitude of the resistor, the etching and deposition process will terminate prior to contact, forming an atomic scale gap. The atomic scale contacts and gaps formed according to this method are useful as a variety of Nano sensors including chemical sensors, biosensors, hydrogen ion sensors, heavy metal ion sensors, magneto resistive sensors, and molecular switches.

Method and device using Nano porous membrane for detecting and quantifying heavy metal ions in a fluid by anodic stripping voltammetry

US9134267B2

Method and a device for capturing heavy metal ions included in sewage sludge. The method includes steps of:

placing in the fluid a functionalized radio grafted track-etched membrane FRTEM which contains polymer Nano pores; this membrane including a first electrode on one side of the membrane,
selectively capturing heavy metal ions inside the polymer Nano pores,
applying an anodic stripping voltammetric ASV analysis on the membrane in order to differentiate and quantify captured metal ions, the first electrode being used as an ASV detection electrode.

Facile method for making non-toxic biomedical compositions comprising hybrid metal-polymer micro particles

United States Patent 9872916

The present invention includes photochemical method of making hybrid metal-polymer micro particles in an aqueous, biocompatible solution by providing a metal (I) composition and one or more polymeric materials; applying an electromagnetic radiation to the metal (I) composition; converting the metal (I) composition to a metal (0) composition; forming one or more hybrid metal-polymer micro particles from the metal (0); capping the one or more hybrid metal-polymer micro particles; and stabilizing the one or more hybrid metal-polymer micro particles with the one or more polymeric materials to prevent agglomeration.

The production process of optical Nano sensor based on polymer nanocomposite for quick detection of small amounts of toxic ions with special groups in its structure can accurately detect ions in the aquatic environment by creating specific interactions with target ions in the aquatic environment by causing a change in the color, detected by eye. The core-shell structure of this Nano sensor has led to high thermal and chemical resistance. Due to the simplicity of synthesis, fastness, repeatability, and reliability in results, it can be used simultaneously for the detection and thorough elimination of heavy metal ions in the aquatic environment and at a vast range of concentrations. Many analytical methods are available for the detection and determination of small amounts of toxic ions. Even though these methods have high sensitivity and low detection limit, they have some restrictions due to their failure to respond to specific cases such as mercury ion, as well as the device being large and expensive. On the other hand, the function of a chemical sensor based on changing color is very simple and sensitive, and it has great importance because of its low limit of detection and visual determination without costly equipment requirements and also, its high detection speed with commercialization capability in the field of the aquatic pollutants.

Controlling and managing the pollutants is strenuous. However, to preserve the water supplies, they must be managed properly. The presence of the vast types of pollutants in water affects the life of the ecosystem, as well as human health and hygiene. The life of aquatic animals and other organisms face severe hazards due to pollutants; many species of aquatic animals, especially in rivers, have been extinct so far. These pollutants also make the natural and aquatic landscapes hideous and unpleasant, and they can adversely affect the attraction of tourists. The wastewater of industries, small workshops, and restaurant contains high amounts of organic and inorganic pollutants, which should not be discharged directly into the rivers and lakes without being refined.

The quality of water is a determining factor in people's welfare. Nowadays, in societies with chemical-polluted waters, many deaths are due to water pollution since disease spreading is inevitable. Even though the drinking water is treated, some water resources in urban areas still have hazardous amounts of potential pathogenic factors. Chemical and toxic compounds cannot be observed in drinking water at all, even on low scales, and it is difficult to comment on the water quality, without conducting special tests. In industrial societies, diverse sources enter the chemical pollution in the water. The awareness of pollutant resources and the attempt to control the water affordably and harmlessly for the environment is so important. Water quality control, at any scale, is challenging due to the diversity and complexity. Because of these challenges, nanomaterials-based sensors have attracted massive attention among researchers, especially after the promising reports of nanowire sensors and quantum dots. Regarding the new features of nanomaterials-based sensors, it is possible to detect multi-purpose pollutants in very low concentrations and to analyze water quality quickly.

Since the industrial revolution, using heavy metals, particularly for plating, steel, and agriculture industries, along with machinery and mining operations, has severely damaged the environment. Harmful problems and hazards have been created for both environment and humans by entering all kinds of heavy and toxic ions into the environment. These kinds of ions can be scattered in elements of Earth, such as water, soil, and air. In this way, they can enter the body in little amounts. Some heavy metals, including copper, magnesium, manganese, and zinc, are available in the human diet since they are necessary for maintaining the body's metabolism in low concentrations. However, some other metals including arsenic, cadmium, mercury, lead, and tin, have higher toxic levels, and their current amount in the environment is higher than the recommended amount. High concentrations of toxic ions damage the living tissues due to their non-biodegradability as well as their ability to accumulate in living tissues. Therefore, determining the low amounts of these ions has a fundamental importance in food chemistry, agriculture, and environmental pollution monitoring as well as maintaining it. Regarding the high concentration of toxic ions and non-biodegradability as well as their ability to accumulate in living tissues, these ions cause damage to living tissues. Some of these ions can cause severe poisoning and even death.

According to the reports, the ion of Mercury can have destructive impacts such as memory loss and a decrease in fertility in humans. Moreover, regularly absorbing a slight amount of Lead can seriously harm the brain, kidneys, and body. Therefore, detecting and determining low amounts of these ions are essential in food chemistry, agriculture, and maintaining and pollution monitoring of the environment. On the other hand, developing a sensitive and accurate instrument for measuring these ions has become a tremendous challenge. There are various kinds of analytic methods to detect and designate slight amounts of toxic ions. However, these methods with high sensitivity and low detection limits have restrictions due to their large size and high costs, which have increased the popularity of the new, fast, portable, and affordable technologies in the last two decades. Chemical sensors based on color changing, which are very sensitive, are easy to be used. These are so important because of their low detection limit, high acceleration, and visual detection, which does not require expensive equipment. In this regard, any efforts to provide a method of designing, synthesis, and application of optical Nano sensors with commercialization capability in the field of aquatic pollutant area would be precious.

Solution of problem

There are laboratory and device measurement methods, such as flame atomic absorption device, inductively coupled plasma spectroscopy, cold vapor, electro thermal atomic absorption spectroscopy, etc. In this regard, the flame atomic absorption device is generally appropriate for measuring concentrations higher than 0.5 milligrams per liter of Lead ion. Measuring the lower concentrations requires preparation and preconcentration, however, detection of mercury ions is restricted with this device. The other mentioned methods, with high sensitivity and low detection limit, have some restrictions due to being costly, unpotable, and large. Optical chemical Nano sensors are very important for the accurate detection and designation of toxic ions. Fast and easy synthesis, high stability and reproducibility, low detection limit, portability, economic affordability, and commercialization capability of synthetic Nano sensors to be applied in the water and wastewater industry are the issues that show the high value of this method. Specific monomers with heteroatoms such as oxygen, nitrogen, sulfur, etc., which can selectively interact with toxic ions, are used in the chemical structure of this Nano sensor. With this interaction, ions preconcentration will be done on the sensor surface. The changing color due to the specific interaction of the sensor with present ions in the aquatic environment specifies the type of target ions and their exact number.

It would be like the visual detection has occurred in a blink of an eye. Also, the types and amounts of ions will be determined accurately without any specific device and operator. The study is about optical Nano sensors of heavy metal ions based on titanium oxide, an inorganic material, in nano dimensions and polymer composite containing hydrophilic groups. This chemical sensor, an indicator of the presence or absence of heavy metal ions in water and aquatic environment, is a gray powder that by being poured into the water sample, shows whether any metal ion is present in the sample. It will be done by changing the sensor color to the customized colors for each specific metal ion.

By putting a small amount of the powder into the water sample and stirring a bit, after 5 minutes the changing color would be visible; this is the powder action mechanism. For instance, if the gray color of the sensor changed to green in the water contained toxic ions, it means that that sample contained copper metal ions, or, if it changed to purple, it means that that sample had mercury ions ( ). Moreover, if no color change occurred, it means that the sample was safe and was not contained the previously checked metal ions and that their color-changing was customized. It should be mentioned about this indicator powder that the higher intensity of the color means the higher concentration of the metal ion in the sample water. This information, in comparison with the table prepared before, could show the precise amount of heavy metal ions in the sample water up to 1 ppb accuracy, which equals 1 microgram per liter ( ).

In this section, the structure of indicator powder is defined scientifically, and its accurate structure is studied:

To synthesize polymeric nanocomposite, a monomer with oxygen and nitrogen heteroatoms for selective absorption, along with a transversal connector to create a three-dimensional network, and also, dithizone ligand for complexing with heavy metal ions was used. Acrylamide hydrophilic monomer was used since it can interact and create complex with heavy metal ions due to electron-donating heteroatoms such as nitrogen and oxygen. Also, because of their hydrophilic properties, the penetration of water with target ions into the nanocomposite and hydrophilic crust will be increased. Due to the monomer and the transverse connector polymerization, the achieved polymer has a powder state and white color. As a result, it does not cause a disturbance in detecting the color change caused by the presence of ions.

A transverse connector in the nanocomposite gives a three-dimensional structure to polymeric nanocomposite and increases the penetration of ions into the network; in other words, it participates in the trapping of ions. Although selective ligand is highly sensitive to complexing with heavy metal ions, its utilization is restricted in chemical reactions due to its hydrophobic property. Modification of this ligand and turning it into a monomer to participate on the surface of modified inorganic nanoparticles in the presence of other hydrophilic factors contribute to its high dispersion in the aquatic environment. Synthetic nanocomposite contained polymeric ligand crust is the sensitive and selective sensor for absorption and visual detection of heavy metal ions in aquatic environments in optimal situations. Some of its salient features are quick designation with one test, highly selective function, and low cost for detecting the heavy metal ions pollution in aquatic solution to prevent wasting of time and finance, and easy to conclude in (In-situ) environment.

This Nano sensor is for selective absorption and visual detection of heavy metal ions such as mercury, lead, cadmium, uranium, and copper. The gray color of this Nano sensor with the detection limit of ppb, in the presence of mercury, lead, cadmium, uranium, and copper, turns respectively, into purple, red, orange, yellow, and green.

There is a significant and straight relation between the concentration of target ions in the aquatic environment and the intensity of changing the color of the sensor, and the detecting time is less than 5 minutes after the connection of Nano sensor and water pollutant.

Regarding the detecting process, the Nano sensor will be added to the aquatic environment at a slight amount (15 milligrams of Nano sensor in the volume of 10-milliliter aquatic pollutant) in the form of powder. The presence of toxic ions and their possible concentration will be approved by the possible changing color of the Nano sensor.

This Nano sensor has a high physical and chemical stability against environmental damage, and accurate results in several cycles in a row have been observed due to this feature.

The synthesized optical Nano sensor in real environments such as urban water, rivers, and seas has been examined, and its usage has been approved.

In the detection process, there is no need for complicated preparation steps of laboratory samples and pre-concentration methods, as well as device methods and operators. Moreover, the non-toxicity materials in the structure of the Nano sensor and the high safety of working with are considered its other characteristics.

The selective function for absorbing the mentioned ions in the presence of other interfering ions, such as calcium, magnesium, nickel, cobalt, and iron, has been investigated and approved.

The synthetic Nano sensor is conveniently portable and affordable. Also, it can be commercialized to be used in water and wastewater industries.

The Polymeric Nanocomposite Synthesize Steps

The Synthesis of

Nanomaterials

Ammonium sulfate with

was placed at 75 C for 2 hours. Adding 1.5 molar ammonia into the reaction solution drop by drop, a white precipitate was obtained, which calcinated at 400

temperature for 4 hours. Eventually, 25 nanometers of white nanoparticles of

were obtained. The accuracy of the synthesis of about 3 grams of nanoparticles was proven by various analyses.

The Investigation of Nanoparticles of

with Infrared Spectroscopy

The FT-IR method, in which the synthesized nanoparticles of

containing hydroxyl groups are on the sample surface, was applied to prove the synthesis of nanoparticles. The IR spectrum of the sample was prepared by producing the KBr pill in the prevalent method. The absorption peak in the 1800-cm region is related to the vibrations of the

-

bond, while the broad peak in the 3200 to 3600 region is related to the stretching vibrations of the OH bond on

surfaces ( ).

The XRD (X-Ray Diffraction) Analysis of

Nanoparticles

By conducting different analyses and obtaining various spectra to prove the synthesis of nanoparticles, analysis of the x-ray diffraction pattern provided intriguing results about the crystallographic structure of nanoparticles. As it is shown in figure 3, the x-ray diffraction of

synthetic nanoparticles corresponds to XRD standard spectrum. The distinct peaks in the positions of

, and

, which have been assigned to the anatase phase of

, approve the accuracy of synthesis and its conformity to nanoparticles

The Investigation of Surface Morphology and Size of

Nanoparticles

SEM analysis, while confirming the preservation of the particle size in nano dimensions, and the relatively uniform morphology of the surface, confirms the size of the nanoparticles to be around 35 nm ( ).

TGA and DSC Thermal Analysis

The thermal analysis gravimetry and differential scanning calorimetry method were used to investigate and prove the synthesis and also thermal stability of the intended nanocomposite. The TGA test was conducted to investigate and discover the behavior of the substances against the heat, and DSC analysis was used to examine the curve obtained from the heat flux concerning temperature or time. Regarding the curves, it becomes clear that there was no significant weight loss; this shows the high thermal resistance of synthesized nanoparticles. Moreover, the graph represents heat generation and weight loss in temperatures below 150

are related to removing the moisture of the prepared product ( ).

Two-Step Modification of

Nanoparticles

First, to modify the surface of

nanoparticles, amine-containing silane compounds ((3-aminopropyl) triethoxysilane) were used. In the second step, a polymerization starter (alpha-bromoisobutyryl bromide) was used to create the intended functional group to start the polymerization from the surface of nanoparticles by creating a bromine functional group to polymerize the living radicals ( ).

The Investigation of The Modified

Nanoparticles Synthesis With Infrared Spectroscopy

To investigate and prove the synthesis of modified nanoparticles in two steps, FT-IR analysis was used. As shown in the figure below, the peak in the 1-cm 1689 region, which is related to amid bond vibrations, represents a successful synthesis of this stage and proves the formation of the bond between nanoparticles and two organic binding agents ( ).

Polymerization

Acrylamide hydrophilic monomer and modified ligand of dithizone, which vinyl functional group has been placed on it in DMF solvent in a nitrogen atmosphere, was used to living radical polymerization on the surface of the

nanoparticles. Then, polymerization ligand and necessary copper metals for polymerization, and eventually, the modified substrate of

nanoparticles were added to the reaction. The reaction was placed at 60

for 5 hours and, the last step was washed several times with ethanol for purification. In this project, a dithizone-based colorimeter sensor with a simple detecting method for small amounts of toxic ions was prepared from aquatic environments. The function of the color sensor for detecting the ions is based on selective interaction between target ions with nitrogen and dithizone sulfur electron pairs, which are existed in polymeric nanocomposite structures in the aquatic environment that has been examined with the naked eye and ultraviolet spectrophotometry.

The structure of the optical Nano sensor was used using different methods of device analysis, and some of the detection methods will be discussed in this section:

Synthesis with Infrared Spectroscopy (FT-IR)

Examining the FT-IR spectrum, based on the figure below, showed that amidic substitutions related to acrylamide at 1-cm 1680 and phenyl ring substitution associated with sensor vinylation at 1-cm 1590 were formed. The 2800-2900 region peaks indicate the

group of the polymeric chain, while the wide peak at the top of the 3000 regions indicates the hydroxylic groups and amines in the polymeric nanocomposite structure ( ).

X-Ray Diffraction (XRD) Analysis of Polymeric Nanocomposite

With different analyzes and obtaining diverse spectra to prove the synthesis of the polymeric nanocomposite, intriguing results of the crystallographic structure of the product was presented by XRD pattern analysis. As shown in figure 3, the XRD pattern of polymeric nanocomposite is obvious. The distinct peaks are in

and

which are for nanoparticles particularly. In the region of 10-30 beside them, the expansion shows the presence of an amorphous polymer layer in the structure of nanoparticles, which approves the successful polymerization on the surface of nanoparticles.

The Investigation of The Nanoparticles Size and Surface Morphology by SEM Analysis

The scanning electron microscope analysis was used to examine the size of nanocomposite particles and their surface morphology. In figure, the sphericity of particles along with synthesis in the Nano dimension (particles with less than 50 nanometers) as well as their integrity can be observed. The maintenance of the sphericity and morphology of the nanocomposites after the polymer formation on nanoparticles is obvious. This size of particles in the scale of Nano is beneficial for a better scattering of the powder and a better color changing in the aquatic environment.

X-Ray Diffraction Spectroscopy

XRD Spectroscopy was used to approve the presence of essential elements in the chemical structure of the sensor. It can be observed in figure that the presence of Oxygen, Carbon, Nitrogen, Titanium, Sulfur, and Silicon elements is approved by using this analysis and mapping.

Optimization of The Effective Factors

In the absorption process, some factors like pH and absorption duration are effective on the amount of absorption. The intended sensor was used on mercury, lead, cadmium, uranium, copper, zinc, nickel, cobalt, iron, silver, aluminum, and chrome by their salts, which at last, the ability of visual detection of mercury, lead, cadmium, copper, uranium, and cadmium was proved.

The pH Optimizing In The Process of Mercury, Lead, Cadmium, Uranium, and Copper Ions Absorption

For adjusting and optimizing the absorption stage, 200 milligrams of synthesized polymeric nanocomposite and 25 milliliters of a water solution of the salts of intended ions with 10 ppb concentration were prepared. The effect of pH on the absorption of the ions by polymeric nanocomposite in 2, 4, 6, 8, and 10 pH was investigated ( ).

The best pH to achieve the highest yield for ion absorption was determined, along with investigating UV-vis spectra and also visual investigation. The visual investigation can be defined as making solutions of metal salts with different concentrations and then observing a noticeable color changing thoroughly by adding the sensor. The pictures of these tests are in the following.

The Optimizing Mercury, Lead, Cadmium, Uranium, and Copper Ions Absorption Time

To adjust and optimize the effective time factor in the absorption of ions by polymeric nanocomposite, 200 milligrams of the polymeric nanocomposite, and 25 milliliters of each of the metals salt water solution with 10 ppb concentration were analyzed. This factor was determined in optimized pH, the best pH for absorption of each of the ions. Along with UV-vis spectrum and visual examination, the best time for achieving the highest yield in ion absorption was assigned, which was 5 minutes; it means the best color changing due to Nano sensor interaction with ions has been achieved in this time. About visual investigation, it can be defined as making solutions of metal salts with different concentrations and then observing a noticeable color changing thoroughly by adding the sensor. The pictures of these tests are in the following.

Determining The Limit of Detection (LOD) of Heavy Metal Ions

For this purpose, 200 milligrams of polymeric nanocomposite and 25 milliliters of water solution with the salts of ions in concentrations of 100, 10, 1, 0.1, 0.01, 0.001 ppm were prepared. The limit of detection (LOD) at optimized pH was detected by eye ( ) and by the device and its amount was reported based on ppb. As it is apparent in this figure, the color changing of the Nano sensor was different in the presence of each four ions, and it was unique for every ion. The followings are some of the main properties of this Nano sensor: its easy application in environmental conditions without the need for intricate and costly equipment and devices, low detection limit, high response speed, the possibility of high recovery and reproducibility, and selective detection of target ions in the detection environment.

The Investigation of the Interfering Ions Impact

Since mercury, cadmium, lead, uranium, and copper metal ions have high interaction with the heteroatoms of the polymeric nanocomposite, it was inevitable to prove their selectivity in this project; in fact, it proves that the intended nanocomposite in sufficient time and appropriate pH in the presence of other metal ions like magnesium, zinc, etc. still maintains its selectivity, and reports the intended ion and concentration faultlessly. Hence, it was proved that solutions of metal ions such as mercury, cadmium, lead, uranium, and copper, with the concentration of 100 ppb in the presence of polymeric nanocomposite, and this time, with a specific concentration ( to 1000 ppm) of other metal ions ( zinc, aluminum, magnesium, sodium) which were prepared individually, had no sign of intervening ions, and the final result reported that there were not any intervening effects from other ions, and polymeric nanocomposite with its specific selectivity detects mercury, cadmium, lead, uranium, and copper ions

The Investigation of the Real Samples

For examining the efficiency of polymeric nanocomposite in detecting each mercury, lead, cadmium, uranium, and copper ion in natural and real samples, the synthetic sensor was tested in the Tiete river in the city of Sao Paulo, which contains effluents of the petrochemical industry. In addition, this sensor was tested in the effluent sample of a petrochemical plant in southern Iran, as well. The result showed that the samples, which appeared clear water samples, contained a significant concentration (1 ppb) of mercury ion Detecting and measuring heavy metal ions has turned into a challenging issue for the relevant regulatory organizations in different communities due to their adverse effects. Therefore, creating quick, convenient, and inexpensive methods for detecting these ions has become a vital principle. Diverse methods have been developed to meet these demands.

Although these methods show good detection limits and liner domains, they need intricate, massive, and non-portable equipment and devices. Unlike these expensive methods, optical sensors have shown tremendous capability in this regard. The synthesized polymeric sensor of this project has significant advantages, including quick detection and rapid response, high selectivity and sensitivity, simplicity of preparation, vast liner domain, and low detection limit, compared with previous studies. The results show that a synthesized polymeric sensor for visual detection of mercury, lead, cadmium, uranium, and copper ions in the aquatic environment is very appropriate, and shows a very low detection limit for these ions. This chemical sensor, which is an indicator of the presence or absence of heavy metal ions in water and aquatic environments, is a gray powder that will be added to the intended water sample, and its color will change to the colors that were already customized for each ion. By changing color, the sensor will show whether the metal ion is present in the sample. This sensor functions by being added in slight amounts to the water and stirred. Then, by waiting around 5 minutes, the change in the color would be observed.

This chemical sensor, an indicator of the presence or absence of heavy metal ions in water and aquatic environment, is a gray powder that by being poured into the water sample, shows whether any metal ion is present in the sample. It will be done by changing the sensor color to the customized colors for each specific metal ion. By putting a small amount of the powder into the water sample and stirring a bit, after 5 minutes the changing color would be visible; this is the powder action mechanism. For instance, if the gray color of the sensor changed to green in the water contained toxic ions, it means that the sample contained copper metal ions, or, if it changed to purple, it means that that sample had mercury ions ( ). Moreover, if no color change occurred, it means that the sample was safe and was not contained the previously checked metal ions and that their color-changing was customized. It should be mentioned about this indicator powder that the higher intensity of the color means the higher concentration of the metal ion in the sample water. This information, in comparison with the table prepared before, could show the precise amount of heavy metal ions in the sample water up to 1 ppb accuracy, which equals 1 microgram per liter ( ).

The Polymeric Nanocomposite Synthesize Steps

The Synthesis of

Nanomaterials

Ammonium sulfate with

temperature for 4 hours. Eventually, 25 nanometers of white nanoparticles of

The Investigation of Nanoparticles of

with Infrared Spectroscopy

The FT-IR method, in which the synthesized nanoparticles of

-

surfaces ( ).

The XRD (X-Ray Diffraction) Analysis of

Nanoparticles

, and

, which have been assigned to the anatase phase of

, approve the accuracy of synthesis and its conformity to nanoparticles

The Investigation of Surface Morphology and Size of

Nanoparticles

TGA and DSC Thermal Analysis

are related to removing the moisture of the prepared product ( ).

Two-Step Modification of

Nanoparticles

First, to modify the surface of

The Investigation of The Modified

Nanoparticles Synthesis With Infrared Spectroscopy

Polymerization

nanoparticles were added to the reaction. The reaction was placed at 60

Synthesis with Infrared Spectroscopy (FT-IR)

X-Ray Diffraction (XRD) Analysis of Polymeric Nanocomposite

and

The scanning electron microscope analysis was used to examine the size of nanocomposite particles and their surface morphology, the sphericity of particles along with synthesis in the nano dimension (particles with less than 50 nanometers) as well as their integrity can be observed. The maintenance of the sphericity and morphology of the nanocomposites after the polymer formation on nanoparticles is obvious. This size of particles in the scale of nano is beneficial for a better scattering of the powder and a better color changing in the aquatic environment.

X-Ray Diffraction Spectroscopy

XRD Spectroscopy was used to approve the presence of essential elements in the chemical structure of the sensor. It can be observed in that the presence of Oxygen, Carbon, Nitrogen, Titanium, Sulfur, and Silicon elements is approved by using this analysis and mapping.

Optimization of The Effective Factors

For adjusting and optimizing the absorption stage, 200 milligrams of synthesized polymeric nanocomposite and 25 milliliters of a water solution of the salts of intended ions with 10 ppb concentration were prepared. The effect of pH on the absorption of the ions by polymeric nanocomposite in 2, 4, 6, 8, and 10 pH was investigated

Determining The Limit of Detection (LOD) of Heavy Metal Ions

For this purpose, 200 milligrams of polymeric nanocomposite and 25 milliliters of water solution with the salts of ions in concentrations of 100, 10, 1, 0.1, 0.01, 0.001 ppm were prepared. The limit of detection (LOD) at optimized pH was detected by eye and by the device and its amount was reported based on ppb. As it is apparent in this figure, the color changing of the Nano sensor was different in the presence of each four ions, and it was unique for every ion. The followings are some of the main properties of this Nano sensor: its easy application in environmental conditions without the need for intricate and costly equipment and devices, low detection limit, high response speed, the possibility of high recovery and reproducibility, and selective detection of target ions in the detection environment.

The Investigation of the Interfering Ions Impact

The Investigation of the Real Samples

For examining the efficiency of polymeric nanocomposite in detecting each mercury, lead, cadmium, uranium, and copper ion in natural and real samples, the synthetic sensor was tested in the Tiete river in the city of Sao Paulo, which contains effluents of the petrochemical industry. In addition, this sensor was tested in the effluent sample of a petrochemical plant in southern Iran, as well. The result showed that the samples, which appeared clear water samples, contained a significant concentration (1 ppb) of mercury ion

Advantage effects of invention

1 Providing synthetic Nano sensors in the form of identification kits for use on an industrial scale

2 Very high physical and chemical stability

3 optical Nano sensor of heavy metal ions based on titanium oxide mineral in nano dimensions and polymer composite containing hydrophilic groups.

: FT IR spectrum of TiO2 nanoparticles

: X-ray diffraction pattern of TiO2 and polymer nanocomposite

: TGA and DSC curves for TiO2 nanoparticles

: Schematic of modified TiO2 center

: FT IR spectrum of modified TiO2

: FT IR spectrum of polymer nanocomposite

: Optimizing pH in the adsorption process of mercury, lead, cadmium, uranium and copper ions

: Uv vis spectrum of polymer nanocomposite in the presence of different concentrations of toxic ions.

: FT IR spectrum of TiO2 nanoparticles

: X-ray diffraction pattern of TiO2 and polymer nanocomposite

: TGA and DSC curves for TiO2 nanoparticles

: Schematic of modified TiO2 center

: FT IR spectrum of modified TiO2

: FT IR spectrum of polymer nanocomposite

Examples

Regarding the detecting process, the Nano sensor will be added to the aquatic environment at a slight amount (15 milligrams in the volume of 10-milliliter aquatic pollutant) in powder form. The presence of toxic ions and their possible concentration will be approved by the possible changing color of the sensor. This Nano sensor has a very high physical and chemical stability against environmental damage, and due to this feature accurate results in several cycles in a row have been observed. The synthesized optical Nano sensor has been examined in real environments, such as urban water, rivers, and seas, and its usage has been approved.

The design, synthesis and application of optical sensors are used in the water industry, sewage and as a result of extraction operations including mines, plating industry, steel industry, machinery and agricultural industries and enter the human life cycle.

Claims

The process of producing the optical Nano sensor based on the UV-vis spectrum of polymeric nanocomposite in the presence of different concentrations of toxic ions and eye detection of heavy metal ions by the solution of mercury, cadmium, uranium, and copper ions with 100 ppb concentration.
According to claim number 1, the intended research is the optical Nano sensor of heavy metal ions based on titanium oxide mineral material in Nano dimensions and polymeric composite containing hydrophilic groups.
According to claim number 2, a chemical sensor, which is in fact an indicator and designator of the presence or absence of heavy metal ions in water and aquatic environments, is a gray powder that by being added to the intended water sample, while its color is changing to the customized color of each ion, is analyzed, simultaneously.
According to claim number 3, this powder functions by being added in slight amounts to the water and stirred. Then, by waiting around 5 minutes, the change in the color would be observed.