▎ 摘　　要

NOVELTY - Preparation of nano zinc oxide-gold nanoparticles-based electrochemical sensor involves vertically dripping graphene oxide suspension on pretreated glassy carbon electrode (GCE), drying to obtain graphene-modified GCE, coating nano zinc oxide-gold nanoparticles composite on electrode, drying to obtain graphene nano zinc oxide-gold nanoparticles-based GCE electrode, placing the electrode in the 3-hydroxypropionic acid aqueous solution, reacting at constant temperature to obtain 3-hydroxypropionic acid modified-electrode, placing 3-hydroxypropionic acid modified-electrode in buffer containing N-hydroxysuccinimide (NHS) and heat preserving, dripping silk fibroin-specific antibody solution on the electrode, drying, and washing unfixed antibody with phosphate-buffered saline to obtain the antibody-graphene-nano-zinc oxide-gold nanoparticles-modified GCE electrode, sealing non-specific binding sites exist on electrode surface with bovine serum albumin (BSA) solution, washing and drying. USE - Preparation of nano zinc oxide-gold nanoparticles-based electrochemical sensor for detecting silk fibroin. ADVANTAGE - The method enhances the electrochemical response signal of sensor and produces electrochemical sensor with high fibroin detection sensitivity. DETAILED DESCRIPTION - Preparation of nano zinc oxide-gold nanoparticles-based electrochemical sensor involves (s1) dissolving graphene oxide in deionized water, ultrasonically processing to obtain graphene oxide suspension, (s2) adding urea (CO(NH2)2) and zinc chloride in molar ratio of 1.5-2.5:1 to deionized water-absolute ethanol solution, dissolving, heating to 75-80degrees Celsius under stirring condition for 1-2 hours, filtering and washing to obtain zinc carbonate-zinc hydroxide hydrate (ZnCO3.2Zn(OH)2.H2O), vacuum drying in oven and calcining in muffle furnace to obtain light yellow nano-zinc oxide powder, (s3) adding chloroauric acid solution to deionized water, adding sodium carbonate solution while stirring with stirrer, adding sodium borohydride solution several times until the color of the solution turns to wine red, continuously stirring to complete reaction to obtain gold nanoparticle solution, (s4) adding same amount of nano-zinc oxide powder to gold nanoparticle solution, ultrasonically disperse to obtain nano zinc oxide-gold nanoparticle composite, (s5) pre-treating glassy carbon electrode (GCE) by polishing the working glassy carbon electrode on the suede with nano alumina and deionized water, soaking in absolute ethanol for ultrasonic cleaning, and washing with deionized water, (s6) vertically dripping graphene oxide suspension on the surface of the pretreated GCE, and drying to obtain graphene-modified GCE, coating nano zinc oxide-gold nanoparticles composite on electrode and drying to obtain graphene nano zinc oxide-gold nanoparticles-based GCE electrode, and (s7) placing the electrode in the 3-hydroxypropionic acid aqueous solution, reacting at constant temperature to obtain 3-hydroxypropionic acid modified-electrode, placing 3-hydroxypropionic acid modified-electrode in buffer containing 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) and heat preserving in constant temperature box to convert the terminal carboxy group of 3-hydroxypropionic acid into active ester of NHS, dripping silk fibroin-specific antibody solution on the surface of the electrode, drying, and washing the unfixed antibody with phosphate-buffered saline (PBS) to obtain the antibody-graphene-nano-zinc oxide-gold nanoparticles-modified GCE electrode, sealing non-specific binding sites exist on the electrode surface with bovine serum albumin (BSA) solution, washing with PBS buffer, and drying.