Pt/Au bimetallic hierarchical structure with micro/nano-array via photolithography and electrochemical synthesis: From design to GOT and GPT biosensors

A novel matrix for enzyme immobilization was successfully developed by using Pt/Au bimetallic hierarchical structure with micro/nano-array to generate highly sensitive biosensors for glutamic oxaloacetic transaminase (GOT, EC 2.6.1.1) and glutamic pyruvic transaminase (GPT, EC 2.6.1.2) determination. The structures of the Pt/Au particles were confirmed with a dual-beam FIB image, transmission electron microscopy (TEM), selected area electron diffraction (SAED) pattern, and X-ray diffraction (XRD) pattern. The morphologies of the Pt/Au bimetallic hierarchical structure before and after enzyme modification were checked using scanning electron microscopy (SEM). The effects of Nafion membrane and enzyme loading were established. Both GOT and GPT activities have been investigated singly and sequentially. The sensing performances were recorded by employing cyclic voltammetric and chronoamperometry (concentration variations of GOT and GPT) techniques. The interference of ascorbic acid and uric acid was also included. We believe that this study will provide a good inspiration in the development of new generation amperometric biosensors. (C) 2009 Elsevier B.V. All rights reserved.