Highly ordered gold-nanotube films for flow-injection amperometric glucose biosensors

Abstract

A high surface area of electrodes along with rapid and efficient electron and ion transfer is essential for the development of high-performance electrochemical biosensors. Here, we present a simple and effective shadow evaporation method for the preparation of highly ordered gold (Au)-nanotube films for use as biosensor electrodes. This unique electrode structure results in a large surface area for enzyme immobilization, increased electrode electricity, and accelerated diffusion of electrolyte ions. When electrochemical reactions were tested, the Au-nanotube film electrode exhibits quasi-reversible and diffusion controlled behaviours. The flow-injection amperometric system for glucose biosensors is fabricated using the Au-nanotube films, and resulted in a fast response time of approximately 4 s, a sensitivity of 1.64 μA mM⁻¹, a limit of detection of 0.07 mM, and a linear detection range of 2–20 mM. Moreover, the interference responses from oxidizable species such as ascorbic acid and uric acid are negligible at an operating potential of −0.1 V.