Nanostructured gold deposited in gelatin template applied for electrochemical assay of glucose in serum

Abstract

Gelatin-templated gold nanostructures were fabricated in order to improve the sensitivity of non-enzymatic determination of glucose. The three-dimensional cavities were created by crosslinking of gelatin layer on the electrode and the specific saw tooth-like morphology of surface was formed by electrodeposition of gold through the cavities. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for the investigation of nanostructure growth and characterization of prepared surfaces. Glucose was detected by a direct electrochemical oxidation during cyclic voltammetry in alkaline solution with excellent sensitivity of 1165μAmM⿿1cm⿿2, wide linear range from 32μM to 10mM and limit of detection (LOD) of 90μM. During amperometric measurements LOD of 1.5μM was achieved. The sensor was able to detect real concentrations of glucose in deproteinized human serum with negligible interference of oxidizable blood components. Great correlation with results obtained from reference methods (commercial glucometer and standard kit for photometric glucose detection) was demonstrated; the determination of glucose in serum was performed with relative standard deviation of 4%. The sensor exhibits a strong potential as a rapid and sensitive non-enzymatic approach in future applications for clinical analyses.