Non-Enzymatic Glucose Biosensor Based On Ag Decorated By PPy/HAP Composite

Glucose detection receives attention in many areas,such as medical diagnosis and clinical analysis,food and textile industry,biotechnology industry and environmental monitoring,etal.Non-enzymatic glucose electrochemical sensing method,in many detection methods,has attracted considerable attention because of its prominent advantages.In this work,we used hydroxyapatite(HAP),a natural biological material with good biocompatibility and biological activity,as a templet to assemble a novel non-enzymatic glucose sensor.The template was modified by polypyrrole(PPy)for improving its electric conductivity.SEM,EDS,XRD and FT-IR were employed to characterize PPy,HAP and PPy/HAP composite.The results indicate there are abundant microtubes orderly arranging in HAP template,and PPy forms a wonderful tubular structure in the microtube array.Based on the results,we constructed a non-enzymatic sensor with PPy/HAP composite and Ag-Hg alloy(PPy/HAP/Ag-Hg)for glucose sensing.The cyclic voltammetry method and current-time method were used to study the sensing performance toward glucose in 0.1 M phosphate buffer solution(pH=7.4).The results show that the sensor exhibits two linear concentration ranges of 0.500-11.0 mM and 14.0-17.5 mM glucose,the sensitivities are 0.231 and 2.21 μA mM-1 cm-2,respectively,and the minimum detection limit is 0.27 mM(S/N=3).Furthermore,the constructed sensing electrode PPy/HAP/Ag-Hg shows excellent performances when several interfering species,such as sodium chloride,ascorbic acid,uric acid and dopamine,co-exists in a glucose solution.At the same time,it also shows good detection stability and reproducibility.In view of the biocompatibility of HAP,the similarity between testing environment and human blood,as well as the above excellent features,it is believed that the PPy/HAP/Ag-Hg sensor has the value of application in vivo detection.