Expanded gate type field effect transistor sensing array and preparation method and application thereof

Abstract

The invention relates to an expanded gate type field effect transistor sensing array and a preparation method and application thereof.The expanded gate type field effect transistor sensing array comprises a silk-screen printing electrode array and a metal oxide semiconductor field effect transistor, the silk-screen printing electrode array comprises a silver electrode and a carbon electrode, and the metal oxide semiconductor field effect transistor comprises a gate, a source and a drain. The carbon electrode is used as a detection probe after being modified by a gold / metal organic framework composite nano material and a detection probe based on a double-recognition strategy, and the carbon electrode is connected with the grid electrode through a wire to obtain the expanded grid type field effect transistor sensing array. Compared with the prior art, the novel extended gate type field effect transistor sensor for rapidly and sensitively detecting antibiotics is simple in structure, low in cost, high in stability and reusable. The double-recognition strategy probe based on combination of the aptamer and the molecularly imprinted polymer is prepared, the detection sensitivity and selectivity are improved, the synthesis method is simple, and experiment conditions are mild.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensor arrays, and relates to an extended gate field effect transistor sensor array and a preparation method and application thereof, and specifically relates to an extended gate field effect transistor sensor array based on a dual recognition strategy and a preparation method and application thereof. Background Art

[0002] Single target molecule detection is often insufficient to provide valuable information for identifying complex samples. In recent years, new detection technologies with high throughput and multi-target detection capabilities have attracted increasing attention. Sensor arrays can simultaneously identify and detect multiple target molecules, and are superior to single target detection in terms of higher throughput, less sample and reagent consumption, shorter analysis time, and reproducible sensor signals. Antibiotics are widely used as antimicrobial agents to treat human and animal diseases. However, overuse and improper handling of antibiotics lead to the risk of losing their effectiveness. The main problem now is that multiple antibiotics often coexist in different types of samples, which highlights the urgency of developing antibiotic multi-target detection technologies. Traditional analytical techniques such as enzyme-linked immunosorbent assay (ELISA), high performance liquid chromatography (HPLC), capillary electrophoresis-mass spectrometry (CE-MS), and liquid chromatography-mass spectrometry (LC-MS) have high sensitivity and selectivity, but are time-consuming, costly, and complex sample pretreatment, making it difficult for these technologies to achieve simultaneous detection of multiple analytes in complex samples. Despite the continuous development of new detection technologies, multi-target detection still faces challenges such as insufficient sensitivity, complex sample preparation, expensive instruments, and laborious operation.

[0003] Extended gate field effect transistor (EGFET) is a promising sensing platform with advantages such as high sensitivity, real-time response and easy miniaturization and integration. Compared with traditional field effect transistors, EGFET can overcome the potential instability problem caused by direct contact between the conductive channel and the target molecule. The extended sensing electrode can be customized using various electrode substrates and modified materials to adapt to different application requirements and scenarios. EGFET sensing system is expected to provide reliable on-site analysis for complex environmental, food and biological samples. Existing EGFET sensor arrays have been used to detect biomarkers. In addition, some biorecognition probes have high affinity and design flexibility, but the failure of probes and interference between sensors hinder the correct quantification of recorded data, thereby limiting the application of these probes in sensing arrays. Therefore, to develop reliable and accurate multi-target sensor arrays, we must first pay attention to recognition strategies and sensing probes.

[0004] To extract analytes from complex matrices, EGFET sensors can utilize selective recognition elements such as antibodies, aptamers, enzymes, or molecularly imprinted polymers (MIPs). Aptamers have high specificity, good biocompatibility, and are easy to functionalize and customize. However, as biomolecules, aptamers are relatively inadequately stable, which hinders their application. In contrast, MIPs have high stability and low cost, but their application is limited by relatively weak affinity and susceptibility to interference from structurally similar compounds. Considering the limitations of a single recognition element in a complex environment, integrating aptamers with predetermined affinity into a polymer cavity will produce hybrid receptors with enhanced recognition properties.

[0005] At present, the extended gate field effect transistor sensor array technology based on the dual recognition strategy has not been reported. Chinese patent application CN115266884A discloses a carbon nanotube transistor flexible ion sensor array and its preparation method, which realizes the detection of three kinds of ions. Through patent comparison, although the transistor sensor array is constructed in this patent, it mainly relies on a specific detection probe ion sensitive membrane, and this recognition strategy is difficult to extend to other sensing applications.

[0006] In terms of transistor sensing technology for antibiotics, Chinese patent application CN115575469A discloses an antibiotic sensor based on high-performance graphene transistors, its preparation method and application, which realizes the detection of tetracycline. However, its detection probe is built on the semiconductor channel of the transistor, and the performance of the semiconductor channel may be affected by device differences and the detection environment, resulting in potential instability of the sensor. In addition, the detection limit is relatively high, which is difficult to meet the requirements of trace detection in practical applications. Summary of the invention

[0007] The purpose of the present invention is to provide a dual recognition strategy extended gate field effect transistor sensor array and its preparation method and application, which are used to overcome the above-mentioned technical problems such as difficulty in detecting multiple analytes in complex samples, relatively high detection limits, and difficulty in meeting the requirements of trace detection in practical applications, and utilize the advantages of high sensitivity of the dual recognition strategy and high stability of the extended gate field effect transistor to realize the detection of trace antibiotics, and realize the specific detection of multiple antibiotics by constructing a sensor array.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] The first aspect of the present invention provides an extended gate field effect transistor sensor array, characterized in that the extended gate field effect transistor sensor array includes a screen-printed electrode array and a metal oxide semiconductor field effect transistor, the screen-printed electrode array includes a silver electrode and a carbon electrode, the metal oxide semiconductor field effect transistor includes a gate, a source and a drain, the carbon electrode is modified by a gold / metal organic framework composite nanomaterial and a detection probe based on a dual recognition strategy and used as a detection probe, the carbon electrode of the dual recognition strategy detection probe in the screen-printed electrode array is connected to the gate of the metal oxide semiconductor field effect transistor by a wire, and an extended gate field effect transistor sensor array based on a dual recognition strategy is obtained.

[0010] Furthermore, the screen-printed electrode array uses a flexible insulating substrate, the flexible insulating substrate is selected from at least one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or polyimide (PI), and the carbon electrodes and silver electrodes are arranged on the same plane layer of the flexible insulating substrate. The flexible insulating substrate is preferably polyethylene terephthalate.

[0011] Furthermore, the carbon electrode uses antibiotics and corresponding specific aptamers to prepare detection probes, respectively, and the antibiotic is at least one of ampicillin (AMP), amoxicillin (AMO) or kanamycin (KAN); the nucleotide sequence of the specific aptamer of ampicillin is shown in SEQ ID NO: 1, the nucleotide sequence of the specific aptamer of amoxicillin is shown in SEQ ID NO: 2, and the nucleotide sequence of the specific aptamer of kanamycin is shown in SEQ ID NO: 3.

[0012] Furthermore, the diameters of the silver electrode and the carbon electrode are 3 mm, and the electrode spacing between the silver electrode and the carbon electrode is 2 mm.

[0013] The second aspect of the present invention provides a method for preparing an extended gate field effect transistor sensor array, wherein the method for preparing a detection probe based on a dual recognition strategy comprises the following steps:

[0014] S1: dissolving copper nitrate, trifluoroacetic acid and polyvinyl pyrrolidone in a mixture of ethanol and N,N-dimethylformamide, and then mixing with meso-tetrakis(4-carboxyphenyl)porphine ferric chloride and heating to react to obtain the metal organic framework material, dispersing the metal organic framework material in water to obtain a metal organic framework material dispersion; adding chloroauric acid and sodium borohydride to the metal organic framework material dispersion to form a mixed aqueous solution, and obtaining a gold / metal organic framework composite nanomaterial after centrifugal washing and drying;

[0015] S2: drop the gold / metal organic framework composite nanomaterial dispersion described in step S1 onto the surface of the carbon electrode and let it dry naturally; dissolve the antibiotic-specific aptamer and the corresponding antibiotic in a phosphate buffer solution for one incubation to obtain a solution containing the specific aptamer and the corresponding antibiotic and drop-coat and fix it on the surface of the carbon electrode, then drop the corresponding antibiotic on the carbon electrode again for a second incubation; wash with water and immerse in a dopamine solution for cyclic voltammetry electropolymerization; finally, place the carbon electrode in a mixture of sodium dodecyl sulfate and acetic acid, stir and elute, and wash with water to obtain a dual recognition strategy detection probe.

[0016] Furthermore, in step S1, the mass ratio of the copper nitrate to meso-tetra(4-carboxyphenyl)porphine ferric chloride is 1:(1-2); the molar concentration of the trifluoroacetic acid in the mixed solution is 0.25-2.5 μM; the mass concentration of the polyvinyl pyrrolidone in the mixed solution is 0.0625-0.135%; in the heating reaction, the reaction temperature is 70-90°C and the reaction time is 3-5h.

[0017] Furthermore, in step S1, the molar ratio of chloroauric acid to sodium borohydride is 1:(2-3), and the mass concentration of the metal organic framework material in the mixed aqueous solution is 0.01-0.05%.

[0018] Furthermore, in step S2, the drop coating amount of the gold / metal organic framework composite nanomaterial dispersion is 5-10 μL; in the first incubation, the molar ratio of the specific aptamer to the corresponding antibiotic is 1:(1-3), and the incubation time is 0.5-2 h; the molar ratio of the corresponding antibiotic in the second incubation to the corresponding antibiotic in the first incubation is 1:(1-3), and the incubation time is 0.5-2 h.

[0019] Furthermore, in step S2, in the one incubation, the drop-coating amount of the solution of the specific aptamer and the corresponding antibiotic is 5-10 μL.

[0020] Furthermore, in step S2, the concentration of the dopamine solution is 2-10 mM, the solvent is phosphate buffer, and in the cyclic voltammetry electropolymerization, the scanning voltage is -0.5 V to 0.5 V, the scanning speed is 50 to 100 mV / s, and the number of scanning circles is 10 to 14 circles; the mass concentration of the sodium dodecyl sulfate is 2-5%, and the volume concentration of the acetic acid is 0.5-2%; in the elution, the elution time is 40-60 min.

[0021] Furthermore, in step S2, the scanning numbers corresponding to ampicillin, amoxicillin and kanamycin are 14, 10 and 12 respectively.

[0022] The third aspect of the present invention provides an application of an extended gate field effect transistor sensor array, wherein the extended gate field effect transistor sensor array based on a dual recognition strategy is used for the qualitative or quantitative detection of ampicillin, amoxicillin or kanamycin, comprising: connecting the source, drain and silver electrodes of the metal oxide semiconductor field effect transistor in the extended gate field effect transistor sensor array based on the dual recognition strategy to a semiconductor analyzer respectively, and after dripping a detection solution containing three antibiotics and incubating, selective detection of the three antibiotics can be achieved, wherein the incubation time is 10-20 minutes; the silver electrodes are connected to the semiconductor analyzer via wires.

[0023] Furthermore, when the extended gate field effect transistor sensor array based on the dual recognition strategy is used for simultaneous detection of three antibiotics, the detection method specifically includes the following steps:

[0024] 1) Plotting a standard curve: The transfer curve was used to record the response of the extended gate field effect transistor sensor array based on the dual recognition strategy to different antibiotics at different concentrations, with the threshold voltage change value (ΔV th ) as the ordinate, and the logarithm of the antibiotic concentration as the abscissa to draw a standard curve, and obtain the antibiotic detection fitting equation;

[0025] 2) Detection of antibiotics in actual samples: Using the same amount of detection solution as in step 1), the treated sample to be tested is dripped onto the electrode array, and the transfer curve of each carbon electrode is tested to obtain the threshold voltage change value (ΔV th ), and then the corresponding antibiotic concentration is obtained according to the standard curve or fitting equation of each antibiotic.

[0026] Compared with the prior art, the present invention has the following characteristics:

[0027] 1) The present invention prepares a dual recognition strategy probe based on the combination of aptamer and molecular imprinting polymer, which improves the sensitivity and selectivity of detection, has a simple synthesis method and mild experimental conditions;

[0028] 2) The present invention builds an extended gate field effect transistor sensor array based on a flexible substrate screen-printed electrode array, and proves through response tests and selectivity tests that it has the effect of accurate quantitative detection in complex samples and has good selectivity for different antibiotics;

[0029] 3) The present invention provides a novel extended gate field effect transistor sensor for rapid and sensitive detection of antibiotics. The extended gate field effect transistor has the advantages of simple structure, low cost, strong stability and reusability. The sensor has a wide detection range (6 orders of magnitude) and high sensitivity, with a detection limit of fM level, which is suitable for accurate detection of low-concentration trace pollutants;

[0030] 4) The extended gate field effect transistor sensing technology based on the dual recognition strategy proposed in the present invention has high versatility and scalability, and can be widely used in environmental, food, biological and other field analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of the extended gate field effect transistor sensor array constructed in Example 1;

[0032] Description of the markings in the figure:

[0033] 1-drain, 2-source, 3-gate, 4-wire, 5-metal oxide semiconductor field effect transistor, 6-silver electrode, 7-carbon electrode, 8-screen printed electrode array;

[0034] Figure 2 Schematic diagram of the dimensions of the screen-printed electrode array in Example 1;

[0035] Description of the markings in the figure:

[0036] a-diameter of carbon electrode and silver electrode, b-electrode distance between carbon electrode and silver electrode;

[0037] Figure 3 The transfer curve (a) and the corresponding output characteristic curve (b) of the extended gate field effect transistor sensor constructed in Example 2;

[0038] Figure 4 The graphs of the transfer curves tested in the preparation process of the detection probe based on the dual recognition strategy in Example 2 ((a) AMP, (b) AMO, (c) KAN);

[0039] Figure 5 Response diagram of the extended gate field effect transistor sensor array based on the dual recognition strategy in Example 3 to three antibiotics ((a) AMP, (b) AMO, (c) KAN) at different concentrations;

[0040] Figure 6 The standard curves for the three antibiotics ((a) AMP, (b) AMO, (c) KAN) drawn in Example 3;

[0041] Figure 7 Comparison diagram of the response of the extended gate field effect transistor sensor array based on the dual recognition strategy in Example 4 to different coexisting interfering antibiotics ((a) AMP, (b) AMO, (c) KAN);

[0042] Figure 8Response diagram of the extended gate field effect transistor sensor array based on the dual recognition strategy in Example 5 to antibiotics ((a) AMP, (b) AMO, (c) KAN) in different actual samples. DETAILED DESCRIPTION

[0043] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0044] In the following examples, unless otherwise specified, raw materials, reagents or processing techniques are all conventional commercial products or conventional processing techniques in the art.

[0045] In the following examples, antibiotics (AMP, AMO and KAN) were purchased from Aladdin Chemical Reagent Co., Ltd.; three antibiotic-specific aptamers were obtained by exponential enrichment ligand system evolution technology and provided by Shanghai Shenggong Biotechnology Co., Ltd., China; tap water and river water were obtained from Tongji University, milk and honey were purchased from a local supermarket in Shanghai, and artificial urine was purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0046] Embodiment 1:

[0047] This embodiment provides an extended gate field effect transistor sensor array. Figure 1 The structural schematic diagram of the extended gate field effect transistor sensor array constructed in this embodiment, the extended gate field effect transistor includes a screen printed electrode array 8 and a metal oxide semiconductor field effect transistor 5 (MOSFET, Texas Instruments CD4007UBE); the screen printed electrode array 8 includes a silver electrode 6 (silver control electrode) and three carbon electrodes 7 (carbon working electrodes), the carbon electrode 7 is modified by a gold / metal organic framework composite nanomaterial and a detection probe based on a dual recognition strategy as a detection probe, the screen printed electrode array 8 uses a flexible insulating substrate PET, and the screen printed electrode array 8 with a carbon working electrode and a silver control electrode is prepared by a screen printing machine. The size schematic diagram of the screen printed electrode array 8 is shown in FIG. Figure 2 As shown, it can be seen that the carbon electrode 7 and the silver electrode 6 in the screen-printed electrode array 8 are both disk electrodes with a diameter a of 3 mm, wherein the electrode spacing b between the carbon electrode 7 and the silver electrode 6 is 2 mm; Figure 2The three carbon electrodes 7 were fixed with three antibiotic-specific aptamers (AMP aptamer (nucleotide sequence as shown in SEQ ID NO: 1: 5′-SH-GCG GGC GGT TGT ATA GCGGTT TTT TT-3′), AMO aptamer (nucleotide sequence as shown in SEQ ID NO: 2: 5′-SH-TTA GTT GGG GTTCAG TTG G-3′) and KAN aptamer (nucleotide sequence as shown in SEQ ID NO: 3: 5′-TGG GGG TTG AGG CTAAGC CGA C-3′)) and corresponding antibiotics (AMP, AMO and KAN) to prepare detection probes, wherein SH in the nucleotide sequence is a thiol group. The detection probe is a dual recognition strategy detection probe, which is specifically obtained by modifying a carbon electrode with gold / metal organic framework composite nanomaterials and a molecular imprinting polymer-aptamer hybridization probe; the metal oxide semiconductor field effect transistor 5 MOSFET includes a gate 3, a source 2 and a drain 1, and the carbon electrode 7 modified with the dual recognition strategy detection probe in the screen-printed electrode array 8 is connected to the gate 3 of the metal oxide semiconductor field effect transistor 5 with a wire.

[0048] The specific preparation method of the detection probe based on the dual recognition strategy comprises the following steps:

[0049] A): 24 mg of copper nitrate, 400 μL of 1 M trifluoroacetic acid ethanol solution and 100 mg of polyvinyl pyrrolidone are dissolved in a mixture of 40 mL of ethanol and 120 mL of N,N-dimethylformamide, and then mixed with 44 mg of meso-tetrakis(4-carboxyphenyl)porphine ferric chloride to obtain a mixed solution;

[0050] B): subjecting the mixed solution obtained in step A) to ultrasonic treatment, heating at 80° C. for 4 h, washing, and drying in sequence to obtain the metal organic framework material, and dispersing the metal organic framework material in water to obtain a metal organic framework material dispersion;

[0051] C): 20 μL of 0.1 mM chloroauric acid aqueous solution and 50 μL of 0.1 mM sodium borohydride aqueous solution were added to 10 mL of 0.1 mg / mL metal organic framework material aqueous dispersion obtained in step B) and mixed evenly, centrifuged at 10000 rpm for 10 min, and vacuum dried at 40° C. for 12 h to obtain a gold / metal organic framework composite nanomaterial;

[0052] D): The gold / metal organic framework composite nanomaterial obtained in step C) is dispersed in water to obtain a gold / metal organic framework composite nanomaterial dispersion liquid with a concentration of 0.1 mg / mL, and the dispersion liquid is drop-coated on the surface of the carbon electrode 7 of the screen-printed electrode array 8, the diameter of the carbon electrode 7 is 3 mm, and the drop-coating amount is 10 μL. The dispersion liquid is dried naturally and then used for later use;

[0053] E): 10 μM specific aptamer and 10 μM corresponding antibiotics (AMP, AMO and KAN) were dissolved in phosphate buffer and incubated for 1 hour to obtain 3 solutions containing specific aptamers and corresponding antibiotics. Then, 3 solutions containing 10 μL of specific aptamers and corresponding antibiotics were respectively dripped and fixed on the three carbon electrodes 7 prepared in step D) for 1 hour, and 10 μL of phosphate buffer with a concentration of 10 μM corresponding antibiotics was dripped and incubated for 30 minutes.

[0054] F): After rinsing with ultrapure water, immersing in 5 mM dopamine aqueous solution for cyclic voltammetric electropolymerization, the scanning voltage is -0.5 V to 0.5 V, the scanning speed is 50 mV / s, and the scanning number of AMP, AMO and KAN is 14, 10 and 12 circles respectively;

[0055] G): The electrode array was placed in a mixed aqueous solution of 5% w (g) / v (mL) sodium dodecyl sulfate and 1% v / v (mL) acetic acid and stirred for 45 minutes, and then rinsed with ultrapure water to obtain a dual recognition strategy detection probe.

[0056] Embodiment 2:

[0057] In this embodiment, the source 2, drain 1 of the MOSFET in the extended gate field effect transistor in embodiment 1 and the silver control electrode in the screen-printed electrode array 8 are respectively connected to a semiconductor analyzer (Keithley 2612B digital source meter, Tektronix, USA) for analyzing the electronic characteristics and sensor signals of the sensor, and a source-drain voltage V DS =0.5V, apply gate voltage V to the silver control electrode REF =0-3V, test the transfer curve.

[0058] like Figure 3 As shown in FIG. 1 , the transfer curve (a) and the corresponding output characteristic curve (b) of the extended gate field effect transistor sensor constructed in Example 1 are shown. Figure 3 It can be seen that the extended gate field effect transistor has n-type FET characteristics and a large switching ratio, indicating the superiority of the transistor sensor. In addition, the threshold voltage (V th ) can be obtained from the transfer curve by drawing a tangent line at the maximum transconductance point on the transfer curve and extracting the intersection of the horizontal axis. The threshold voltage change value (ΔV th) served as the sensor response in subsequent tests.

[0059] like Figure 4 As shown, the transfer curve changes tested during the preparation of the detection probe based on the dual recognition strategy in Example 1 are shown ((a) AMP, (b) AMO, (c) KAN). After the extended gate electrode (EG) was modified with gold / metal organic framework composite nanomaterials (AuNPs / MOF) (i.e., the electrode modified in step D), the transfer curve showed a slight left shift. The sheet-like metal organic framework material allows the gold nanoparticles to grow uniformly, which enables the aptamer to be fixed and provides a large surface area that is beneficial for increasing the imprint cavity. Incubation of the aptamer-antibiotic complex (Apt (AMP), Apt (AMO), Apt (KAN)) (i.e., the electrode modified in step E)) causes the transfer curve to shift to the right, which is a result of the effect of the aptamer on the double layer capacitance. The subsequent dopamine polymerization (MIP, i.e., the electrode modified in step F)) causes the transfer curve to shift further to the right, which is mainly due to the polymer layer causing the gate 3 electrode capacitance to decrease, resulting in a decrease in the MOSFET gate 3 induced voltage, V th Increase.

[0060] Embodiment 3:

[0061] In this example, the extended gate field effect transistor sensor array based on the dual recognition strategy prepared in Example 1 was used to detect three antibiotics, AMP, AMO and KAN, and the real-time dynamic response of the sensor array to different concentrations of the three antibiotics was evaluated to obtain a linear relationship and a fitting equation. The following steps were included:

[0062] (1) The source 2, drain 1, and silver control electrode of the MOSFET in the extended gate field effect transistor are connected to a semiconductor analyzer (Keithley 2612B digital source meter, Tektronix, USA) for analyzing the electronic characteristics and sensor signals of the sensor, and a source-drain voltage V is applied. DS =0.5V, apply gate voltage V to the silver control electrode REF =0-3V;

[0063] (2) Phosphate buffer (pH = 7) was used as the detection solution, and antibiotic solutions of different concentrations were prepared with this buffer. The initial transfer curve of the sensor was first tested, and 10 -14 -10 -8 After incubation in the antibiotic solution for 15 min, the corresponding transfer curve was tested to reflect the response of the sensor to different concentrations of antibiotics.

[0064] The results are as follows Figure 5 As shown in the figure, it can be seen that as the concentration of the added antibiotic increases, the transfer curve gradually shifts to the right. th) as the ordinate and the logarithm of the antibiotic concentration as the abscissa to draw a standard curve ( Figure 6 ), and the antibiotic detection fitting equation (AMP: ΔV th =21.86lg[AMP]+318.16(R 2 =0.991), AMO: ΔV th =18.02lg[AMO]+273.67(R 2 =0.998), KAN: ΔV th =11.94lg[KAN]+200.37(R 2 =0.992)); According to the detection limit LOD=3σ / N (where σ is the standard deviation of the blank sample and N is the slope of the linear equation), the detection limits were 4.6fM, 1.6fM and 8.6fM, respectively.

[0065] Embodiment 4:

[0066] In this example, the extended gate field effect transistor sensor array based on the dual recognition strategy prepared in Example 1 was used to test the response of the sensor array to other coexisting antibiotics and evaluate the selectivity of the sensor array for the detection of the target antibiotic. The specific steps are as follows:

[0067] Phosphate buffer (pH = 7) was used as the detection solution, and other coexisting antibiotics with a concentration of 1 nM were prepared with the buffer, including tetracycline (TC), ciprofloxacin (CIP), sulfadiazine (SDZ), streptomycin (STR), erythromycin (ERY), chloramphenicol (CAP), and lincomycin (LIN). 100 μL of 1 nM target antibiotic solution and the above non-target antibiotic solution were added dropwise and incubated for 15 min. The threshold voltage (V th ) to examine its selective recognition ability.

[0068] The results are as follows Figure 7 As shown, the sensor has a much smaller response to the above non-target antibiotics than to the target antibiotics, indicating that the constructed extended gate field effect transistor sensor array based on the dual recognition strategy has good selectivity and can specifically recognize the target antibiotics.

[0069] Embodiment 5:

[0070] In this embodiment, the extended gate field effect transistor sensor array based on the dual recognition strategy prepared in Example 1 is used to detect antibiotics in actual samples (tap water, river water, milk, honey and artificial urine). The specific detection process is as follows:

[0071] (1) Pretreatment of samples to be tested: Before testing, tap water and river water samples were simply filtered to remove solid impurities that may be adsorbed on the electrode surface and affect the accuracy of the analysis; trichloroacetic acid was added to the milk sample to precipitate protein, the supernatant was collected by centrifugation and filtered with a 0.22 μm sterile membrane; honey samples were directly filtered with a 0.22 μm sterile membrane for later use; artificial urine was used directly without treatment;

[0072] (2) Detection of antibiotics in actual samples: Take the pre-treated actual sample as the solvent and prepare 10 -14 -10 -8 M three antibiotic solutions, un-spiked samples and samples spiked with antibiotics at different concentrations were added dropwise to test the response of the sensor array respectively (test method and parameters were the same as those in Example 3).

[0073] The results are as follows Figure 8 As shown, the sensor array exhibits consistent responses to antibiotics added to different samples and PBS buffer. The recovery of each antibiotic in all samples was calculated using the fitting equation in Example 3, with a recovery of AMP of 80.6% to 118.9%, a recovery of AMO of 81% to 119.2%, and a recovery of KAN of 82.7% to 116.4%. These results successfully demonstrate that the constructed extended gate field effect transistor sensor array based on the dual recognition strategy can accurately detect multiple antibiotics in complex application scenarios, which is of great significance for environmental pollution detection, food safety management, and therapeutic drug monitoring.

[0074] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An extended gate field effect transistor sensor array, characterized in that: The extended gate field effect transistor sensor array comprises a screen-printed electrode array (8) and a metal oxide semiconductor field effect transistor (5); the screen-printed electrode array (8) comprises a silver electrode (6) and a carbon electrode (7); the metal oxide semiconductor field effect transistor comprises a gate electrode (3), a source electrode (2) and a drain electrode (1); the carbon electrode (7) is modified with a gold / metal organic framework composite nanomaterial and a detection probe based on a dual recognition strategy and serves as a detection probe; the carbon electrode (7) and the gate electrode (3) are connected with a wire to obtain an extended gate field effect transistor sensor array based on a dual recognition strategy.

2. The extended gate field effect transistor sensor array according to claim 1, characterized in that: The screen-printed electrode array (8) uses a flexible insulating substrate, and the flexible insulating substrate is selected from at least one of polyethylene terephthalate, polyethylene naphthalate or polyimide.

3. The extended gate field effect transistor sensor array according to claim 1, characterized in that: The carbon electrode (7) uses an antibiotic and a corresponding specific aptamer to prepare a detection probe, wherein the antibiotic is at least one of ampicillin, amoxicillin or kanamycin; the nucleotide sequence of the specific aptamer of ampicillin is shown in SEQ ID NO: 1, the nucleotide sequence of the specific aptamer of amoxicillin is shown in SEQ ID NO: 2, and the nucleotide sequence of the specific aptamer of kanamycin is shown in SEQ ID NO:

3.

4. The extended gate field effect transistor sensor array according to claim 1, characterized in that: The diameters of the silver electrode and the carbon electrode are 3 mm, and the electrode distance between the silver electrode and the carbon electrode is 2 mm.

5. A method for preparing an extended gate field effect transistor sensor array as claimed in any one of claims 1 to 4, characterized in that: The preparation method of the detection probe based on the dual recognition strategy comprises the following steps: S1: dissolving copper nitrate, trifluoroacetic acid and polyvinyl pyrrolidone in a mixture of ethanol and N,N-dimethylformamide, and then mixing with meso-tetrakis(4-carboxyphenyl)porphine ferric chloride and heating to react to obtain the metal organic framework material, dispersing the metal organic framework material in water to obtain a metal organic framework material dispersion; adding chloroauric acid and sodium borohydride to the metal organic framework material dispersion to form a mixed aqueous solution, and obtaining a gold / metal organic framework composite nanomaterial after centrifugal washing and drying; S2: drop the gold / metal organic framework composite nanomaterial dispersion described in step S1 onto the surface of the carbon electrode and let it dry naturally; dissolve the antibiotic-specific aptamer and the corresponding antibiotic in a phosphate buffer solution for one incubation to obtain a solution containing the specific aptamer and the corresponding antibiotic and drop-coat and fix it on the surface of the carbon electrode, then drop the corresponding antibiotic on the carbon electrode again for a second incubation; wash with water and immerse in a dopamine solution for cyclic voltammetry electropolymerization; finally, place the carbon electrode in a mixture of sodium dodecyl sulfate and acetic acid, stir and elute, and wash with water to obtain a dual recognition strategy detection probe.

6. The method for preparing an extended gate field effect transistor sensor array according to claim 5, characterized in that: In step S1, the mass ratio of copper nitrate to meso-tetra(4-carboxyphenyl)porphine ferric chloride is 1:(1-2); the molar concentration of trifluoroacetic acid in the mixed solution is 0.25-2.5 μM; the mass concentration of polyvinyl pyrrolidone in the mixed solution is 0.0625-0.135%; in the heating reaction, the reaction temperature is 70-90° C. and the reaction time is 3-5 h.

7. The method for preparing an extended gate field effect transistor sensor array according to claim 5, characterized in that: In step S1, the molar ratio of chloroauric acid to sodium borohydride is 1:(2-3), and the mass concentration of the metal organic framework material in the mixed aqueous solution is 0.01-0.05%.

8. The method for preparing an extended gate field effect transistor sensor array according to claim 5, characterized in that: In step S2, the drop coating amount of the gold / metal organic framework composite nanomaterial dispersion is 5-10 μL; in the first incubation, the molar ratio of the specific aptamer to the corresponding antibiotic is 1:(1-3), and the incubation time is 0.5-2 h; the molar ratio of the corresponding antibiotic in the second incubation to the corresponding antibiotic in the first incubation is 1:(1-3), and the incubation time is 0.5-2 h.

9. The method for preparing an extended gate field effect transistor sensor array according to claim 5, characterized in that: In step S2, the concentration of the dopamine solution is 2-10 mM, the solvent is phosphate buffer, and in the cyclic voltammetry electropolymerization, the scanning voltage is -0.5 V to 0.5 V, the scanning speed is 50 to 100 mV / s, and the number of scanning circles is 10 to 14 circles; the mass concentration of the sodium dodecyl sulfate is 2-5%, and the volume concentration of the acetic acid is 0.5-2%; in the elution, the elution time is 40-60 min.

10. An application of the extended gate field effect transistor sensor array according to any one of claims 1 to 4, characterized in that: The extended gate field effect transistor sensor array based on the dual recognition strategy is used for the qualitative or quantitative detection of ampicillin, amoxicillin or kanamycin.

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