KR101288921B1 - Method of functionalization of single-walled carbon nanotube field-effect transistor, trimethylamine sensor using the same, and measuring method of seafood freshness using the same - Google Patents

Abstract

PURPOSE: A functionalization method of a single-walled carbon nanotube field-effect transistor (FET) by using a self-assembling peptide, a trimethylamine detection sensor containing a single-walled carbon nanotube FET manufactured by using the same, and a seafood freshness measuring method by using the sensor are provided to improve functions by combining a substance desired for detection with amino acid. CONSTITUTION: A semiconductor channel is constructed with single-walled carbon nanotubes. The single-walled carbon nanotubes are formed on a substrate. Source-drain electrodes are formed at both sides of the semiconductor channel. An amino acid cluster is combined with the terminus of a peptide. The peptide is self-assembled on the surface of the semiconductor channel.

Description

Functionalization method of single-walled carbon nanotube field effect transistor using self-assembled peptide, trimethylamine detection sensor comprising single-walled carbon nanotube field effect transistor manufactured thereby, and seafood freshness measurement method using the same {METHOD OF FUNCTIONALIZATION OF SINGLE- WALLED CARBON NANOTUBE FIELD-EFFECT TRANSISTOR, TRIMETHYLAMINE SENSOR USING THE SAME, AND MEASURING METHOD OF SEAFOOD FRESHNESS USING THE SAME}

The present invention relates to a functionalization method of a single-walled carbon nanotube field effect transistor using a self-assembled peptide, a trimethylamine detection sensor comprising a single-walled carbon nanotube field effect transistor manufactured thereby, and a seafood freshness measuring method using the same.

Recently, attention has been focused on sensors for detecting and analyzing target materials using nanomaterials in various applications. Most olfactory sensors currently being developed are made of a combination of semiconductor or polymeric materials. These sensors are still inferior to the human olfactory system in terms of specificity and do not have high selectivity for individual analytes or species.

Various nanostructure-based transistors, especially single-wall carbon nanotube-field effect transistors (swCNT-FETs), have been extensively studied in high-selectivity biosensors, but single-walled carbon nanotube-field effects for bioelectronic nose applications have been studied. Transistors were not used.

The conventionally developed olfactory sensor system has been commercially available since the mid-1990s. For example, FOX2000 is the first model released by France's Alpha MOS, and GEMINI, KRONOS, and PROMETHEUS are also available. In addition, Aroma in the UK has developed olfactory sensors using conductive polymers, and Cyrano Science in the USA has launched a portable olfactory sensor using polymer conductor chips (Lee, Duk-Dong, Olfactory Sensor Technology, Application and Control). Metrology, 20-23, 2003). All of these models detect odors by using artificially developed carbon-polymer composites, semiconductor materials, etc., but there are limitations in the accuracy of odor detection and specificity for specific odors to be detected.

In order to solve this problem, efforts have been made to use the specificity and accuracy of the original protein by using peptides among olfactory receptors that are present to smell in living organisms, and in fact, the quartz crystal microbalance (QCM) It has been reported that the tissues of the olfactory organs are separated and purified and used as olfactory sensors (Tzong-Zeng Wu, Biosensors & Bioelectronics , 14, 9-18, 1999). However, this method has a disadvantage in that mass production is impossible because animal tissue is directly separated and used as an olfactory sensor.

Intake of spoiled seafood can cause serious health problems such as sepsis and gastroenteritis. Therefore, there is a growing interest in determining the quality of seafood on site in real time, which must satisfy the sensitive and selective detection of volatile compounds from high-end seafood. Many studies have reported that trimethylamine can be used as an effective indicator for the quality measurement of seafood because the amount of trimethylamine is increased by the decomposition of trimethyl-N-oxide in post-seafood. In order to detect trimethylamine, analytical techniques of gas chromatography-mass spectrometry (GC-MS), ion mobility analysis (IMS) and high performance liquid chromatography (HPLC) have been generally used. While this technique has the advantage of accurate quantitative analysis, it presents challenges for making real-time decisions in the field in terms of complex pretreatment processes, large apparatus, and complex detection methods. Interest and development in electronic and biomimetic olfactory sensors continue, but limitations on sensitivity and selectivity still remain to be overcome for practical use.

10-2009-0116652, Transistor Functionalized by Olfactory Receptor Useful as Highly Selective Bioelectronic Nose and Biosensor Using the Same

The present invention provides a method of functionalizing a single-walled carbon nanotube field effect transistor using a self-assembled peptide having high sensitivity and selectivity to solve the above problems, and trimethyl including a single-walled carbon nanotube field effect transistor manufactured thereby. An object of the present invention is to provide an amine detection sensor and a seafood freshness measurement method using the same.

The above objects, features, and advantages will be apparent from the following detailed description with reference to the accompanying drawings, and as a result, those skilled in the art to which the present invention pertains may easily facilitate the technical idea of the present invention. It could be done. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

The present invention has been made to solve the above problems

i) preparing a single-walled carbon nanotube-field effect transistor comprising a substrate, a semiconductor channel consisting of single-walled carbon nanotubes (SWCNTs) formed on the substrate, and source-drain electrodes formed at both ends of the semiconductor channel. step;

ii) binding an amino acid cluster to the peptide end; And

iii) self-assembled peptides comprising the amino acid cluster is bonded to the surface of the semiconductor channel of the single-walled carbon nanotube-field effect transistor; self-assembled peptide comprising a single-walled carbon nanotube electric field A method of functionalizing an effect transistor is provided.

In the present invention, the single-wall carbon nanotube-field effect transistor of step i) can use a single-wall carbon nanotube-field effect transistor commonly used in the art.

That is, the substrate may be selected from the group consisting of a silicon wafer, a III-V semiconductor substrate, a II-VI semiconductor substrate, an epitaxially grown SiGe substrate, glass, quartz, metal, and plastic, but is not limited thereto. Preferably a silicon wafer.

Self-assembled monolayers composed of one or more molecules selected from the group consisting of octadecyltrichlorosilene (OTS), octadecyltriethoxysilane (OTE), and octadecanecyol (ODT) on a silicon substrate , SAM) can be patterned on the substrate. It means a regularly aligned organic molecular film produced on the surface of the substrate, preferably having one of a carboxyl group (-COOH) and / or a hydroxyl group (-OH). Preferably, the material for forming a SAM may be OTS having a nonpolar end group.

The patterning method is not limited, for example, microcontact printing, photolithography, dip-pen nanolithography, e-beam lithography, ion-beam lithography It may be accomplished by ion-beam lithgraphy, nano grafting, nanoshaving or STM lithography. Preferably may be photolithography.

The semiconductor channel may be formed of single-walled carbon nanotubes (swCNTs) among nanostructures. swCNTs are hexagonal honeycomb graphite plates composed of sp2 carbon or carbon allotrope wound in a cylinder shape having a nano-sized diameter. The swCNTs can be functionalized to modify the surface of carbon nanotubes and impart functionality.

The patterned substrate is immersed in a swCNTs containing solution (generally 0.1 mg / ml in dichlorobenzene) and swCNTs are selectively adsorbed onto the exposed substrate, which is the unpatterned site. The swCNT-FET is then fabricated by forming the source and drain electrodes using photolithography.

Source and drain electrodes may be formed on the self-assembled monolayer formed on the substrate except for the semiconductor channel. That is, the source electrode and the drain electrode may be formed directly on the substrate, or may be formed on the self-assembled monolayer.

The source electrode and the drain electrode are each independently platinum, gold, chromium, copper, aluminum, nickel, palladium, titanium, molybdenum, lead, iridium, rhodium, cobalt, tungsten, tantalum, erbium, ytterbium, samarium, yttrium, valent It may be made of a metal selected from the group consisting of dolium, terbium, cerium, and mixtures or alloys thereof. Preferably titanium and gold.

The surface of the substrate and the electrode can then modify the surface of the substrate and the electrode to facilitate the physical or chemical adsorption or attachment of the peptide. For example, the surface of the electrode may be modified to include reactive functional groups or linker molecules such as amino groups, carboxyl groups, oxo groups and thiol groups.

Thereafter, in step ii), the amino acid cluster is coupled to the end of the peptide. In the method of functionalizing a single-walled carbon nanotube field effect transistor using the self-assembled peptide of the present invention, the C terminus of the peptide binds to the amino acid cluster, and the other end binds characteristically to a substance to be detected by a sensor. It features.

In this case, the amino acid is characterized in that it comprises an aromatic functional group capable of π-stacking with the semiconductor channel surface. Specifically, the amino acid is selected from the group consisting of phenylalanine, tryptophan and tyrosine, of which phenylalanine is preferable.

In the functionalization method of a single-walled carbon nanotube field effect transistor using the self-assembled peptide of the present invention, the amino acid cluster is characterized in that it comprises three or more amino acids.

In the present invention, the peptide may be used without limitation so long as it is a peptide that specifically binds to a substance to be detected. In the method of functionalizing a single-walled carbon nanotube field effect transistor using the self-assembled peptide of the present invention, the peptide comprises 10 to 15 amino acids. Peptides of this size are self-assembled in a single-walled carbon nanotube-field effect transistor-based sensor as the binding force is increased by the amino acid cluster attached to the terminal.

In the functionalization method of a single-walled carbon nanotube field effect transistor using the self-assembled peptide of the present invention, the peptide is characterized in that it specifically binds to trimethylamine. The peptide that specifically binds to the trimethylamine is not particularly limited and may be represented by NQLANLSFSDLC.

In the present invention, in step iii), the olfactory receptor peptide is magnetized on the surface of the carbon nanotube by π-π stacking between the aromatic functional group of the amino acid cluster coupled with the olfactory receptor peptide and the swCNTs. Immobilized by assembly, nano-thick olfactory receptor peptides are nano-coated on the surface of the carbon nanotubes.

The present invention also provides a single-walled carbon nanotube-field effect transistor based trimethylamine detection sensor functionalized by a method for functionalizing a single-walled carbon nanotube field effect transistor using the self-assembled peptide of the present invention.

The trimethylamine detection sensor using the single-walled carbon nanotube-field effect transistor based sensor of the present invention can detect trimethylamine in the odorous substance when the concentration of trimethylamine in the odorous substance is 10 fM or more. The functionalized single-walled carbon nanotube-field effect transistor-based trimethylamine detection sensor of the present invention binds phenylalanine clusters to trimethylamine-specific olfactory receptor peptides, thereby improving sensitivity to odorous substances, resulting in trimethylamine at 10 fM or higher. Can be detected

When trimethylamine is bound to the olfactory receptor molecule in the trimethylamine detection sensor using the single-walled carbon nanotube-field effect transistor based sensor, the equilibrium of the receptor molecule shifts to the negatively charged active receptor form. The negative charge of the olfactory receptor molecules changed into the active state modulates the contact resistance between the metal electrode and the single-walled carbon nanotubes (swCNTs), leading to a decrease in conductance.

That is, a single-walled carbon nanotube-field effect transistor-based trimethylamine detection sensor including an olfactory receptor peptide is fabricated, and the sample is reacted to detect a change in conductance depending on whether or not the odorous substance in the sample reacts with the receptor peptide in the olfactory sensor. The presence or absence of trimethylamine can be confirmed by doing this.

According to the present invention, odor with high sensitivity and selectivity based on electrostatic perturbation on single-walled carbon nanotubes (swCNTs) junctions caused by the change in the shape of the receptor by the binding of the olfactory receptor and the odorous substance. The substance can be detected.

The present invention also provides a method for measuring the concentration of trimethylamine, ie, seafood freshness, using the single-walled carbon nanotube-field effect transistor based trimethylamine detection sensor of the present invention. Trimethylamine is produced specifically when seafood decays, and the sensor can distinguish high-end seafood from other types of food by selectively detecting trimethylamine.

That is, a single wall carbon nanotube (swCNTs) -based olfactory sensor containing trimethylamine-specific olfactory receptor peptides may be reacted with a sample to obtain a signal according to a change in time. In an embodiment, the process of making a single-walled carbon nanotube (swCNTs) based olfactory sensor comprising trimethylamine specific olfactory receptor peptide (NQLSNLSFSDLCFFF) and a capping seafood comprising trimethylamine that specifically reacts with the olfactory receptor peptide The sample may be reacted with a SWCNT-FET based olfactory sensor to obtain a change in conductance with time.

According to the functionalization method of a single-walled carbon nanotube field effect transistor using the self-assembled peptide of the present invention, in the functionalization of a single-walled carbon nanotube-field effect transistor as a peptide capable of specifically binding to a substance to be detected, the By binding amino acids containing aromatic functional groups to peptides, the single-walled carbon nanotube field effect transistors can be functionalized using self-assembled peptides in a single process without the functionalization of single-walled carbon nanotube-field effect transistor surfaces. do.

In addition, the single-walled carbon nanotube-field effect transistor based olfactory sensor manufactured by the manufacturing method of the present invention specifically binds trimethylamine in an odorous substance, and enables high-specific detection of trimethylamine up to the range of fM in real time. As a sensor that can be utilized as a possible bioelectronic nose, it can be used to measure the freshness of seafood with high sensitivity.

1 shows a SWCNT-FET coated with olfactory receptors for the detection of trimethylamine.
Figure 2 shows the image confirmed that the FITC complex peptide immobilized through a fluorescent dye picture.
3 shows AFM images of SWCNT-FET channels immobilized with olfactory receptor peptides and SWCNT-FET channels immobilized with olfactory receptor peptides.
4 shows high detection results of the sensitivity and selectivity of trimethylamine from sample solution using SWCNT-FET coated with olfactory receptor peptides.
Figure 5 shows the results of detection of trimethylamine from high-end seafood using SWCNT-FET coated with olfactory receptor peptides.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited by the following examples.

Manufacturing example  1> SWCNT - FET Production

Single-walled carbon nanotube-field effect transistors (swCNT-FETs) have been fabricated by photolithography methods known to those skilled in the art.

The octadecyltrichlorosilylene self-assembled monolayer (OTS SAM) was patterned by photolithography on a silicon (SiO ₂ ) substrate including a silicon wafer to form a nonpolar portion. Purified swCNTs were then dispersed in dichlorobenzene by ultrasonic vibration to form a 0.05 mg / mL swCNTs suspension, and the OTS patterned substrate was immersed in the suspension for about 10 seconds. During the soaking process, swCNTs were specifically absorbed in the exposed SiO ₂ moiety. Dichlorobenzene was rinsed thoroughly. Afterwards, a Ti (10 nm) / Au (20 nm) electrode was fabricated through a conventional photolithography process and covered with an insulating photoresist layer (DNR) to prevent contact with the solution. The gap spacing between the source electrode and the drain electrode was 6 µM.

< Example  1> SWCNT - FET on Peptides  Fixed Condition Check

Fluorescence images were measured by changing the number of phenylalanine bound to glycine and using phenylalanine as an amino acid to establish the immobilization conditions of olfactory receptor peptides bound to the swCNTs channel according to the number of binding of phenylalanine.

Four kinds of FITC-complex peptides (GG, GGF, GGFF, and GGFFF), each having glycine in place of the olfactory receptor peptide and having 0 to 3 phenylalanine in the glycine, have a PEPTRON (www.peptron. com). Glycine was synthesized together for use as a linker of FITC and phenylalanine. The olfactory receptor peptide coupled with phenylalanine was suspended at 1 mg / mL in deionized water (DW). In addition, the four FITC-peptides were suspended at the same concentration (1 mM) for treatment with the same number when analyzing immobilization efficiency. Suspended peptides were frozen at −20 ° C. and dissolved prior to use.

Fluorescent dyes emitted from four immobilized FITC-peptides were imaged using fluorescence microscopy (Olympus). Fluorescence intensity was analyzed using Image J (NIH) from the image and normalized by maximum intensity.

After treating and rinsing the swCNTs channel with the FITC-complex peptide suspension, it was observed that green fluorescence was observed as shown in Fig. 2 (b). Since the bright part is a fluorescent part, it can be seen that the FITC-peptide is specifically immobilized in the line patterned swCNTs channel part. In the above process, it can be seen that the addition of phenylalanine at the end of the peptide can be immobilized in a single step on the swCNTs.

FIG. 2 (c) shows a graph normalizing the intensity of fluorescence emitted from each swCNTs channel in FIG. 2 (b). Of the four peptides synthesized in FIG. 2 (c), the three peptides of the phenylalanine bound peptide showed the brightest fluorescence, and only one phenylalanine was immobilized on the swCNTs channel more than five times more efficiently than the peptide to which the peptide was bound. It was. This result means that the π-system of the aromatic ring of three phenylalanines is most effective for immobilizing the peptide.

< Example  2> olfactory receptors Peptides and  Complex Preparation and Immobilization of Phenylalanine

In this example, (NQLSNLSFSDLCFFF) is used as the olfactory receptor peptide, As the amino acid having an aromatic functional group, three phenylalanines were used in combination.

In order to fix the olfactory receptor peptide bound to the phenylalanine to the SWCNT-FET, 1.5 μL of deionized water in which the olfactory receptor peptide was suspended was placed in the swCNTs channel region of the fabricated chip for 4 hours. For 4 hours, the olfactory receptor peptides were coated with a nanolayer monolayer on the order of 2-3 nm through self-assembly on the swCNTs surface. The chip was then rinsed 3-4 times in deionized water to remove unbound olfactory receptor peptides (FIG. 1).

< Experimental Example  1> AFM Olfactory receptors by Peptides and  Confirmation of Complex Immobilization of Phenylalanine

Two AFM images before and after fixing phenylalanine-linked olfactory receptor peptides to confirm that the surface structure after fixation determines whether or not the olfactory receptor peptides are immobilized on the surface of the field effect transistor (Fig. 3 (a)). And FIG. 3 (b)). AFM imaging was performed under ambient conditions using an AFM system in irregular mode (MFP-3D, Asylum Research).

As shown in FIG. 3 (c), the brightness of swCNTs to which olfactory receptor peptides were immobilized was higher than that of swCNTs not treated with olfactory receptor peptides.

It was also confirmed that the height of swCNTs was increased by the olfactory receptor peptide immobilization process. In particular, as shown in Fig. 3 (c), the height of the cross section was uniformly improved by 2-3 nm. This indicates that the expected height of the olfactory receptor peptide of the α-helix structure by 15 amino acids is approximately 2-3 nm, and the olfactory receptor peptide is uniformly coated with a single layer.

< Experimental Example  2> SWCNT - FET  Sensitivity Verification of Trimethylamine Concentration in the Sensor Based Olfactory Sensors

After the monolayer of the olfactory receptor peptide bound with phenylalanine was formed, the resistance between the source electrode and the drain electrode was measured to confirm the presence of the bound compound.

In a field effect transistor, when a compound is coupled to a channel, the resistance between the source electrode and the drain electrode increases, but the characteristics of the field effect transistor reacting with the gate potential are maintained. Electrical measurements were performed using a probe station (MS tech) and a Keithley 2636A source meter. For the experiment, a voltage of 0.1V was applied between the train and source electrodes while the gate voltage was grounded.

The change in conductance according to the reaction of trimethylamine and olfactory receptor peptide was measured in real time. 49.5 μL of deionized water was placed in the swCNTs channel and sample solution was added. Trimethylamine in the concentration range of 1 fM to 1 nM was reacted with the SWCNT-FET with and without the olfactory receptor peptide, respectively. The reduction in conductance was confirmed from trimethylamine of 10 fM, and the conductance was further decreased as the concentration of trimethylamine was increased (Fig. 4 (a)).

Measured five times and the straight line calculated by the average and the standard deviation is shown in Figure 4 (b). When a solution of 100 μM of trimethylamine was injected, saturation was reached.

In addition, the reaction used a Langmuir isotherm model by standardizing the saturated value. The equilibrium constant was calculated from the Langmuir isothermal equation to give a value of 6.04 × 10 ¹⁰ M ⁻¹ . From the above results, we confirmed that the present invention can sensitively detect low concentrations of trimethylamine, such as 10 fM.

< Experimental Example  3> SWCNT - FET  Selectivity Selection for Trimethylamine in the Base Olfactory Sensors

The SWCNT-FET treated with the olfactory receptor peptide bound with phenylalanine and the olfactory receptor peptide bound with phenylalanine was used in real time to detect trimethylamine from other molecules.

A 100 μM solution was prepared by adding trimethylamine, triethylamine, dimethylamine, 2-methyl-1propanol, ethyl acetate, ethanol, methanol, acetic acid in deionized water, and diluted with deionized water to 1:10. Trimethylamine, triethylamine, dimethylamine, 2-methyl-1propanol, ethyl acetate, ethanol, methanol and acetic acid were all purchased from sigma. The solutions were stored at 4 ° C. until used. 1 nM trimethylamine, 1 nM triethylamine, 1 nM dimethylamine, 1 nM 2-methyl-1propanol, 1 nM ethyl acetate, 1 nM ethanol, 1 nM methanol, 1 nM acetic acid did not cause changes in conductance, but 1 pM Trimethylamine solution caused a sharp change in conductance (Fig. 4 (c)).

In addition, in order to quantitatively confirm the trimethylamine selectivity of the sensor, the result of comparing the reaction intensity of 1 nM trimethylamine solution with that of other compositions of 1 nM is shown in FIG. 4 (d). The strength resulting from trimethylamine had a value that was at least 10 times higher than that of other compositions.

< Experimental Example  4> SWCNT - FET Capping Seafood in Sensor Based Olfactory Sensors Detectability  Confirm

< Experimental Example  4-1> Production of High End Seafood Samples

The trimethylamine detectability was measured from the actually upper seafood sample using the post value sensor manufactured by this invention.

To produce high-end seafood specimens, three fresh seafood oysters (domestic), shrimp (Thailand), and lobster (Canada) were purchased at the local market. Fresh seafood was ground to reduce sample error and stored in a 25 ° C. 15 mL Falcon tube. After storage for 0 to 4 days, 1 mL of deionized water was added per 1 mg of seafood and the liquid was obtained by squeezing the liquid of the capped seafood. Some of the liquid was further diluted 1: 100 with deionized water before conducting the experiment.

< Experimental Example  4-2 Sample Dilution>

Samples diluted 1: 100 were found to have no effect on SWCNT-FET based olfactory sensors without olfactory receptor peptides. The fabricated samples were first treated with SWCNT-FETs that were not coated with olfactory receptor peptides and confirmed that the various compositions contained in high-end seafood had nonspecific effects on conductance. Three high-end seafood samples were treated with SWCNT-FETs that were not coated with olfactory receptor peptides and then measured for conductance changes, indicating no detected response.

< Experimental Example  4-3> SWCNT - FET Sensitivity to high-end oyster samples

The change in conductance was measured in real time while repeatedly processing the upper oyster sample for 2 days. The fabricated sample was processed in a SWCNT-FET based olfactory sensor and the change in conductance was observed (Fig. 5 (a)). The sharp decrease in conductance was similar to the reaction obtained from the trimethylamine solution in this experiment. This shows the detectability of trimethylamine from the upper oysters in real time.

After the measurement, the chip was rinsed 3-4 times with deionized water. The rinsed chips were then stored with deionized water on top of them until they stabilized again to the reference. In this process, the experiment was repeated four times for the same sample and a constant reaction was observed. In particular, the standard deviation from the four reaction intensities was within 3%, meaning that the measurement could be reproduced.

< Experimental Example  4-4> SWCNT - FET Oysters, shrimp, and capping of the olfactory sensor Lobster  Check Sensitivity to Samples

A sharp decrease in conductance was observed by treatment of cold oysters, cold shrimp for 1 day, and cold lobster samples for 2 days. The conductance change by the treatment of the upper oyster, shrimp, and lobster for 0-4 days was measured in real time (Fig. 5 (b)). The reaction strength increased with the degree of rot by increasing the amount of trimethylamine. The increase tendency was quantitatively repeated three to five times. From small standard deviations, this sensor indicates that the measurement can be reproduced (Fig. 5 (c)). The sensor can also be used to determine seafood quality using the ability to convert the reaction strength in a sample solution to the measured concentration of trimethylamine.

< Experimental Example  4-5> SWCNT - FET Oysters, shrimp, and capping of the olfactory sensor Lobster  Check selectivity for sample

To ascertain the ability to distinguish high-end seafood, we additionally produced other types of high-end foods according to the high-end seafood production process above. Milk (domestic), tomatoes (domestic), broccoli (domestic), and beef (domestic) were purchased at local markets. The food was ground to reduce sample error and stored in a 25 ° C. 15 mL Falcon tube. After storage for 0-4 days, 1 mL of deionized water per 1 mg of seafood was added to squeeze the liquid of the high-end seafood to obtain a liquid. Before performing the experiment, some of the liquid was further diluted 1: 100 with deionized water.

After injecting four different food samples, fresh oyster samples and spoiled oyster samples for four days, the real-time conductance changes were measured. The four other foods did not show any effect on conductance from spoiled milk, tomatoes, broccoli, beef and fresh oysters (Fig. 5 (d)). On the other hand, two-day upper oysters showed a sharp decrease in conductance. In light of the above results, the sensor can distinguish specifically spoiled seafood from other spoiled foods and determine the extent of seafood spoilage.

Claims (12)

Preparing a single-walled carbon nanotube-field effect transistor comprising a substrate, a semiconductor channel comprising a single-walled carbon nanotube (SWCNT) formed on the substrate, and a source-drain electrode formed at both ends of the semiconductor channel;
Binding an amino acid cluster to the peptide end; And
Single-walled carbon nanotube field effect transistor using a self-assembled peptide comprising a step of self-assembling the peptide is coupled to the amino acid cluster is bonded to the surface of the semiconductor channel of the single-walled carbon nanotube-field effect transistor How to functionalize.
The method of claim 1,
The amino acid is a method of functionalizing a single-walled carbon nanotube field effect transistor using a self-assembled peptide that comprises an aromatic functional group capable of π-stacking with the semiconductor channel surface.
The method of claim 1,
The amino acid is a method of functionalizing single-walled carbon nanotube field effect transistor using a self-assembled peptide that is selected from the group consisting of phenylalanine, tryptophan and tyrosine.
The method of claim 1,
The amino acid is a phenylalanine method of functionalizing a single-wall carbon nanotube field effect transistor using a self-assembled peptide.
The method of claim 1,
The amino acid cluster is a functional method of a single-walled carbon nanotube field effect transistor using a self-assembled peptide containing three or more amino acids.
The method of claim 1,
The peptide is C-terminal is coupled to the amino acid cluster, the other end is characterized in that the binding to the material to be detected by the sensor characterized in that the single-wall carbon nanotube field effect transistor using a self-assembled peptide.
The method according to claim 1,
The peptide is a method of functionalizing a single-wall carbon nanotube field effect transistor using a self-assembled peptide that specifically binds to trimethylamine.
The method of claim 1,
The peptide is a method of functionalizing a single-walled carbon nanotube field effect transistor using a self-assembled peptide containing 10 to 15 amino acids.
The method of claim 1,
The peptide is a method of functionalizing a single-walled carbon nanotube field effect transistor using a self-assembled peptide that is represented by NQLANLSFSDLC.
Trimethylamine detection sensor comprising a single-walled carbon nanotube field effect transistor functionalized by any one of claims 1 to 9.
11. The method of claim 10,
Trimethylamine detection sensor, characterized in that the detection of trimethylamine in the odorous substance when the concentration of trimethylamine in the odorous substance is 10 fM or more
Method for measuring seafood freshness using the trimethylamine detection sensor of claim 10

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