CN108929242B

CN108929242B - AgNCs @ APAP fluorescent probe, preparation method thereof and application thereof in Hg (II) determination

Info

Publication number: CN108929242B
Application number: CN201811002539.5A
Authority: CN
Inventors: 王治科; 张柏爽; 朱韵怡; 王全坤; 叶存玲; 范顺利
Original assignee: Henan Normal University
Current assignee: Henan Normal University
Priority date: 2018-08-30
Filing date: 2018-08-30
Publication date: 2020-10-16
Anticipated expiration: 2038-08-30
Also published as: CN108929242A

Abstract

The invention belongs to the technical field of fluorescence analysis, and particularly relates to an AgNCs @ APAP fluorescent probe, a preparation method thereof and application thereof in Hg (II) determination. The preparation method of AgNCs @ APAP mainly comprises the following steps: acetaminophen (APAP) (7mL, 50mM) solution was placed in a 50mL jacketed beaker and AgNO added₃The solution (0.3mL, 0.1M) was then added with water to 10 mL and reacted at 55 ℃ with magnetic stirring in the dark for 10 h. Then filtered through a 0.45 μm hydrophilic PTFE needle filter and dialyzed through a 1kDa dialysis bag. The fluorescent probe has the advantages of simple synthesis steps, mild reaction conditions, high fluorescence quantum yield and suitability for long-term storage. A trimerization thiocyanic acid (TCY) -BR buffer solution (pH = 10) -AgNCs @ APAP fluorescent probe Hg (II) system is established and successfully used for determining Hg (II) in a water sample.

Description

AgNCs @ APAP fluorescent probe, preparation method thereof and application thereof in Hg (II) determination

Technical Field

The invention belongs to the technical field of fluorescence analysis, and particularly relates to an AgNCs @ APAP fluorescent probe, a preparation method thereof and application thereof in Hg (II) determination.

Background

After mercury is discharged into water, methyl mercury is generated by the decomposition of bacteria, enters the organism through the food chain, and is accumulated in the organism. In the water body polluted by mercury, the concentration of methyl mercury in the fish body is ten thousand times higher than that in the uncontaminated water. Meanwhile, the methyl mercury is easily dissolved in lipid, is easily absorbed by a human body, is slow in metabolism, high in accumulated toxicity and not easy to decompose, is a high-toxicity nerve agent, is accumulated in the brain, and has damage effects on the kidney and the capillary vessels. Therefore, the method for rapidly, simply, conveniently and sensitively detecting Hg (II) is of great significance to biology and environment. At present, the analysis method for detecting Hg (II) ions is quite complex in instrument and technology, long in time consumption in the sample pretreatment process and high in detection cost.

Disclosure of Invention

The invention aims to provide an AgNCs @ APAP fluorescent probe, a preparation method thereof and application thereof in Hg (II) determination.

In order to achieve the purpose, the invention adopts the technical scheme that the preparation method of the AgNCs @ APAP fluorescent probe comprises the following steps: adding 7mL of 50mmol/L paracetamol solution into a beaker, and then adding 0.3mL of 0.1mol/LAgNO₃And adding 2.7mL of deionized water into the solution, magnetically stirring the solution at the temperature of 55 ℃ in the dark to react for 10 hours, filtering the solution by using a 0.45-micrometer hydrophilic PTFE needle filter, and dialyzing the solution by using a 1kDa dialysis bag to obtain the AgNCs @ APAP fluorescent probe.

The invention has the following beneficial effects: the AgNCs @ APAP fluorescent probe can form a system for measuring Hg (II) by the aid of the AgNCs @ APAP fluorescent probe together with trithiocyanuric acid (TCY) and a BR buffer solution, wherein the pH value of the system is 10, and the system is AgNCs @ APAP fluorescent probe and has the advantages of low detection limit and wide linear range, and can be well used for measuring Hg (II) in a water sample.

Drawings

FIG. 1 is a graph of the UV-VIS absorption spectra of APAP and AgNCs @ APAP;

FIG. 2 is a high resolution transmission electron microscope (a) and electron diffraction pattern (b) of selected regions of AgNCs @ APAP;

FIG. 3 is a graph of the effect of pH (a), storage time (b), ionic strength (c) and exposure time (d) on the fluorescence intensity of AgNCs @ APAP;

FIG. 4 shows fluorescence intensity vs. Hg of the measurement system²⁺A graph of concentration dependence;

FIG. 5 is a graph showing the effect of common metal ions on the Hg (II) measurement system;

FIG. 6 is a graph showing the effect of common metal ions on the fluorescence recovery of the AgNCs @ APAP-TCY system.

Detailed Description

Preparation of AgNCs @ APAP fluorescent probe

AgNCs @ APAP was synthesized by a one-step synthesis method, taking acetaminophen (APAP) (7mL, 50mM) solution in a 50mL jacketed beaker, adding AgNO₃After the solution (0.3mL, 0.1M), 2.7mL of deionized water was added, and the reaction was magnetically stirred at 55 ℃ in the dark for 10 h. Then, the mixture was filtered through a 0.45 μm hydrophilic PTFE needle filter, dialyzed through a 1kDa dialysis bag, and stored at 4 ℃ in the dark for further use.

Characterization of

FIG. 1 is a UV-visible absorption spectrum of APAP and AgNCs @ APAP showing characteristic absorption bands at 200nm, 245nm and 290nm for AgNCs @ APAP demonstrating that AgNCs @ APAP is not the same species as APAP.

FIG. 2 is a high resolution transmission electron microscope (a) and electron diffraction pattern (b) of selected regions of AgNCs @ APAP. As can be seen from FIG. 2(a), the average particle size of AgNCs @ APAP is about 1.29nm, APAP-modified silver nanoclusters are spherical and have uniform size distribution, the insets are lattice structures of particle sizes, and lattice lines are all in the same direction, which shows that the synthesized AgNCs @ APAP structures are uniform. FIG. 2(b) is an electron diffraction pattern of selected regions, showing that the synthesized AgNCs @ APAP has a uniform particle size distribution and consistent crystal properties.

FIG. 3 is a graph showing the effect of pH (a), storage time (b), ionic strength (c) and illumination (d) on the fluorescence intensity of AgNCs @ APAP. As shown in fig. 3(a), pH greatly affects the stability of AgNCs @ APAP, and when pH is 8, the fluorescence intensity is strongest. As shown in FIG. 3(b), the change in fluorescence intensity of AgNCs @ APAP was not large when stored at 4 ℃ for two months in the absence of light, indicating that AgNCs @ APAP had good storage stability. As shown in FIG. 3(c), the fluorescence intensity of AgNCs @ APAP hardly changed with the addition of NaCl. As shown in FIG. 3(d), the fluorescence intensity of AgNCs @ APAP increases slightly after irradiating AgNCs @ APAP with an ultraviolet lamp at 365nm for 90 min.

Hg²⁺Measurement of (2)

0.7mL of 0.5mM thiocyanic acid (TCY) was mixed with 0.2mL of pH 10 BR buffer solution, and Hg was added to the mixture at different concentrations²⁺Reacting at 25 deg.C for 30min, diluting 1mL of 5-fold AgNCs @ APAP solution to 4.00mL, shaking, and standing for 5 minAfter min, the fluorescence intensity F of the system was measured at an excitation wavelength of 323nm (slit width: ex slit: 5.0nm, em slit: 3.8nm), and the blank (Hg) system was used²⁺At a concentration of 0) was recorded as F₀. As shown in FIG. 4, the linear equation is F-F₀/F₀＝0.02683C_Hg ²⁺+0.0973(C_Hg ²⁺Is Hg²⁺Concentration, μ M), correlation coefficient R²When 0.9986, the limit of detection LOD was 0.22 μ M. For the addition of 100 μ M Hg²⁺The fluorescence intensity of the post-AgNCs @ APAP-TCY system was measured in 15 replicates with a Relative Standard Deviation (RSD) of 1.84%.

Anti-interference performance of measuring method

FIG. 5 shows the effect of common metal ions on the Hg (II) measurement system. Common metal ion (Na)⁺、Mg²⁺、K⁺、Zn²⁺、Fe³ ⁺、Ca²⁺、Ba²⁺、Pb²⁺、Cu²⁺、Co²⁺、Ni²⁺、Cd²⁺、Sn²⁺、Bi³⁺) And hg (ii) ions were each 20 μ M in concentration, and at an excitation wavelength of 323nm (slit width: ex slit-5.0 nm, em slit-3.8 nm) was measured. The experimental results show that: fe³⁺、Pb²⁺、Cu²⁺And Bi³⁺The presence of (b) had a slight effect on the assay.

Selectivity of the assay

FIG. 6 is a graph showing the effect of common metal ions on the fluorescence recovery of the AgNCs @ APAP-TCY system. Common metal ion (Na)⁺、Mg²⁺、K⁺、Zn²⁺、Fe³⁺、Ca²⁺、Ba²⁺、Pb²⁺、Cu²⁺、Co²⁺、Ni²⁺、Cr⁶⁺、Cd²⁺、Sn²⁺、Bi³⁺) And hg (ii) ions were each 100 μ M, and after reaction at 25 ℃ for 30min, the mixture was heated at an excitation wavelength of 323nm (slit width: ex slit ═ 5.0nm, emslit ═ 3.8nm) was measured. The experimental results show that: hg is a mercury vapor²⁺The ions maximize the recovery of the fluorescence intensity of the system.

Applications of

Selecting spring water from different regions, mixingPreparation of simulated Hg (II) -containing water sample, Hg²⁺The addition amount of (A) is 20 mu M and 50 mu M respectively, the measurement results are shown in Table 1, the relative deviation of the obtained data is small, and the measured standard addition recovery rate ranges from 94.95% to 101.7%.

Table 1 Hg in water sample²⁺The measured result of the standard adding recovery experiment

Claims

1. A preparation method of an AgNCs @ APAP fluorescent probe is characterized by comprising the following steps: adding 7mL of 50mmol/L acetaminophen solution to the beaker, and then adding 0.3mL of 0.1mol/LAgNO₃And adding 2.7mL of deionized water into the solution, magnetically stirring the solution at the temperature of 55 ℃ in the dark to react for 10 hours, filtering the solution by using a 0.45-micrometer hydrophilic PTFE needle filter, and dialyzing the solution by using a 1kDa dialysis bag to obtain the AgNCs @ APAP fluorescent probe.

2. An AgNCs @ APAP fluorescent probe obtained by the preparation method of claim 1.

3. Use of the AgNCs @ APAP fluorescent probe of claim 2 for the determination of Hg (II).