An Electrochemical Detection Of 1,5-anhydroglueitol Based On Enzyme-catalyzed Silver Deposition

1,5-anhydroglueitol(1,5-AG)as an important biomarker,can reflect blood glucose levels.It is often clinic diagnose and evaluation for diabetes by detecting the concentration of 1,5-AG in human serum.In this paper,the detection of 1,5-AG was studied.The pyranose oxidase enzyme(PROD),immobilized on the surface LAPS chip,was used as an electrochemical probe.A light-addressable potentiometric sensor(LAPS)based on enzyme-catalyzed silver(Ag)deposition was developed for 1,5-anhydroglucitol(1,5-AG)determination.The main contents of the these are as follows:The LAPS biosensor interface was established.Using 1,5-AG as the text object,the Pyranose oxidase,which can specifically recognize 1,5-AG,was identified on the surface of LAPS chip by layer-by-layer self-assembly,and the LAPS biosensor interface was constructed.The immobilization conditions of PROD were optimized,and the molecular weight was enhanced by modifying the nano-gold adsorption layer on the silanized LAPS chip.Using the good bio-compatibility and adsorption of nano-god to fix PROD which can special recognition 1,5-AG to the surface of LAPS chip,increase the stability of immobilized enzyme and effectively maintain the biological activity of immobilized enzyme.Building a LAPS detection system based on LabVIEW platform.The ICL8038 signal generator chip is used to fabricate a portable drive signal source for the LAPS addressing light source.The automatic power control circuit(APC)is the negative feedback control circuit,by controlling the driving current of the laser tube to keep the laser tube output power constant within the operating temperature range.Using the LabVIEW software to build the acquisition system to collect and process the data to achieve the final I-V curve real-time display.The specific detection of 1,5-AG based on the principle of enzyme-catalyzed silver deposition.The catalytic effect of PROD on 1,5-AG was used to generate hydrogen peroxide as a reducing substance.Hydrogen peroxide in the electrolyte solution reduces the silver ion concentration in the solution,which leads to the change of the membrane potential on the surface of the LAPS chip.The change of the membrane potential also reflects the change of the 1,5-AG concentration.The results showed that there was a good linear relationship between the voltage offset and the concentration of 1,5-AG in therange of 60 ?g / mL to 225 ?g / mL.The correlation coefficient was 0.9977 and the detection limit was 40 ?g/m L,the relative standard deviation was 1.37%,1,5-AG The recoveries were in the range of 92.95-103.50% and the specificity was good.