CN-121971078-A - Wearable molecular imprinting sensor and application thereof in cortisol detection

Abstract

The invention discloses a wearable molecular imprinting sensor and application thereof in cortisol detection, and belongs to the technical field of electrochemical analysis and detection. The molecular imprinting sensor sequentially comprises a sweat absorbing pad, a three-electrode system, an annular polydimethylsiloxane mould and a medical adhesive patch from the skin contact surface to the outside, wherein the front surface of the sweat absorbing pad is contacted with the skin, KCl and K 3 [Fe(CN) 6 are adsorbed on the back surface of the sweat absorbing pad, the three-electrode system takes a MIP/AuNWs/PET sensor as a working electrode, a platinum wire as a counter electrode and a silver/silver chloride electrode as a reference electrode, and the annular polydimethylsiloxane mould and the medical adhesive patch form a sweat collecting cavity. The molecular imprinting sensor based on the gold nanowire (AuNWs) grown in situ on the porous PET film provided by the invention is used for rapidly detecting the cortisol level in human sweat in real time, and the molecular imprinting technology is utilized to simulate the interaction of natural receptor ligands so as to realize high-specificity identification on the cortisol.

Inventors

• YU CHUNMEI
• LI MENGWEI

Assignees

• 南通大学

Dates

Publication Date

20260505

Application Date

20251219

Claims (8)

1. 1. The molecular imprinting sensor is characterized in that a sweat absorbing pad, a three-electrode system, an annular polydimethylsiloxane mould and a medical adhesive patch are sequentially arranged from the skin contact surface to the outside; The front surface of the sweat absorbing pad is contacted with skin, and KCl and K 3 [Fe(CN) 6 are adsorbed on the back surface of the sweat absorbing pad; the three-electrode system takes a MIP/AuNWs/PET sensor as a working electrode, a platinum wire as a counter electrode and a silver/silver chloride electrode as a reference electrode; The annular polydimethylsiloxane mold and the medical adhesive patch form a sweat collecting chamber; the MIP/AuNWs/PET sensor takes a PET film as a base film, gold nanowires are grown in situ in film holes of the PET film, and a molecularly imprinted polymer layer is arranged on the surface of the PET film on which the gold nanowires are grown.
2. 2. The molecular imprinting sensor according to claim 1, wherein the MIP/AuNWs/PET sensor is prepared by: step 1, paving a PET film on the surface of a NaOH solution for etching, taking out, and washing with deionized water to obtain a PET nano porous film; Step 2, taking a solution of sodium borohydride, and a mixed solution of chloroauric acid and sodium citrate to react to obtain a gold seed solution, immersing the PET nano porous membrane in a solution of a silane coupling agent after oxygen plasma treatment, immersing the PET nano porous membrane in the gold seed solution after taking out to enable gold seeds to be deposited on the surface of the membrane, and then placing the membrane in a growth solution consisting of chloroauric acid, 2-mercaptobenzoic acid and ascorbic acid to obtain a PET film growing gold nanowires; And 3, placing the PET film growing with the gold nanowires into an acetic acid buffer solution containing monomer o-phenylenediamine and template molecular cortisol, forming a molecularly imprinted polymer layer on the surface through electropolymerization, and then soaking in a mixed solution of ethanol and acetic acid to obtain the MIP/AuNWs/PET sensor.
3. 3. The molecular imprinting sensor according to claim 2, wherein in step 1, the concentration of NaOH solution is 5 mol/L, and the etching condition is room temperature, 2 h.
4. 4. The molecular imprinting sensor according to claim 2, wherein in step 2, the molar ratio of sodium borohydride, chloroauric acid and sodium citrate is 6:0.25:0.5, and the molar ratio of chloroauric acid, 2-mercaptobenzoic acid and ascorbic acid is 12:1:30.
5. 5. The molecular imprinting sensor according to claim 2, wherein in step 2, the silane coupling agent is (3-aminopropyl) triethoxysilane.
6. 6. The molecular imprinting sensor according to claim 2, wherein in step 3, the molar ratio of monomeric o-phenylenediamine to template molecular cortisol is 10:1-30:1, the pH of the acetic acid buffer is 3.0-6.0, the electropolymerization conditions are 0-1V, 20-75 mV/s, 15-35 cycles, and the volume ratio of ethanol to acetic acid is 8:2.
7. 7. The molecular imprinting sensor according to claim 6, wherein in the step 3, the molar ratio of the o-phenylenediamine monomer to the cortisol template molecule is 10:1, the pH of the acetic acid buffer is 3.0-4.0, and the electropolymerization condition is 0-1V, 50 mV/s, 30 cycles.
8. 8. Use of a molecularly imprinted sensor according to any one of claims 1-7 for detecting cortisol, said detection being for non-disease diagnostic therapeutic purposes.

Description

Wearable molecular imprinting sensor and application thereof in cortisol detection Technical Field The invention belongs to the technical field of electrochemical analysis and detection, and particularly relates to a molecular imprinting sensor for in-situ growth of gold nanowires (AuNWs) on a porous polyethylene terephthalate (PET) film, which is used for rapidly detecting cortisol level in human sweat in real time. Background The existing cortisol detection clinical method has certain limitation and is not suitable for real-time monitoring. For example, the ELISA method has relatively simple operation but certain cross reaction, the tandem mass spectrometry method requires professional personnel and expensive equipment, portable detection is difficult to realize, and the radioimmunoassay is gradually replaced by other methods due to radioactivity problem. In contrast, the electrochemical detection method has the advantages of simple operation, strong controllability, short detection period and the like, and can be used for developing a simple miniaturized biosensor. The molecular imprinting biosensor is a novel electrochemical sensor and has the characteristics of short detection time, high sensitivity, low detection limit and the like. Cortisol in sweat is measured using molecular imprinting techniques as reported by Liu et al (Liu H C, et al ANALYTICAL CHEMISTRY, 2023, 95 (44): 16079-88.) with relatively long measurement times, although with low detection limits, yeasmin (YEASMIN S, et al BIOSENSORS & BIOELECTRONICS, 2022, 206.) with short detection times, but with lack of a complete wearable device, which limits the practical application of the sensor. Currently, the study of cortisol sensors is still in the start-up phase. Improving the effective area, conductivity and electrochemical stability of the electrodes is a key way to obtain Molecularly Imprinted Polymer (MIP) biosensors with good stability and excellent sensing properties. In order to solve the problems, with the development of nano materials, the combination of the porous PET film and AuNWs enables the electrode to have high specific surface area and strong electrode activity, can maintain good stability, and is gradually applied to a wearable real-time detection device. Disclosure of Invention One of the purposes of the invention is to provide a molecular imprinting sensor, which comprises a sweat absorbing pad, a three-electrode system, an annular polydimethylsiloxane mould and a medical adhesive patch from the skin contact surface to the outside; The front surface of the sweat absorbing pad is contacted with skin, and KCl and K 3[Fe(CN)6 are adsorbed on the back surface of the sweat absorbing pad; the three-electrode system takes a MIP/AuNWs/PET sensor as a working electrode, a platinum wire as a counter electrode and a silver/silver chloride electrode as a reference electrode; The annular polydimethylsiloxane mold and the medical adhesive patch form a sweat collecting chamber; the MIP/AuNWs/PET sensor takes a PET film as a base film, gold nanowires are grown in situ in film holes of the PET film, and a molecularly imprinted polymer layer is arranged on the surface of the PET film on which the gold nanowires are grown. Further, the MIP/AuNWs/PET sensor is prepared by the following steps: step 1, paving a PET film on the surface of a NaOH solution for etching, taking out, and washing with deionized water to obtain a PET nano porous film; Step 2, taking a solution of sodium borohydride, and a mixed solution of chloroauric acid and sodium citrate to react to obtain a gold seed solution, immersing the PET nano porous membrane in a (3-aminopropyl) triethoxysilane solution after oxygen plasma treatment, immersing the PET nano porous membrane in the gold seed solution after taking out to enable gold seeds to be deposited on the surface of the membrane, and then placing the PET nano porous membrane in a growth solution consisting of chloroauric acid, 2-mercaptobenzoic acid and ascorbic acid to obtain a PET film for growing gold nanowires; and 3, placing the PET film growing the gold nanowire into an acetic acid buffer solution containing monomer o-phenylenediamine and template molecular cortisol, forming a molecularly imprinted polymer layer on the surface through electropolymerization, and then soaking in a mixed solution of ethanol and acetic acid to obtain the MIP/AuNWs/PET sensor. Further, in the step 1, the concentration of the NaOH solution is 5 mol/L, and the etching condition is room temperature and 2h. Further, in the step 2, the molar ratio of sodium borohydride, chloroauric acid and sodium citrate is 6:0.25:0.5, and the molar ratio of chloroauric acid, 2-mercaptobenzoic acid and ascorbic acid is 12:1:30. Further, in step 3, the molar ratio of the monomer o-phenylenediamine to the template molecular cortisol is 10:1-30:1, preferably 10:1, the pH of the acetic acid buffer is 3.0-6.0, preferably 3.0-4.0, the electropolymerization condit