Insect biofuel cell using an electrode with gold nanoparticles deposited by sputtering

A high-stability living battery that uses a metallic catalyst for glucose oxidation instead of enzymes is investigated. In this battery, glucose in insect haemolymph is oxidised by a gold nanoparticle (AuNP)-modified electrode, which is utilised as the anode of the battery. The AuNP-modified electrode was fabricated by sputtering gold onto a carbon cloth in a low-vacuum state. First, the oxidation performance values of glucose were evaluated and the oxidation current of glucose was obtained by the AuNP-modified electrode from cockroach haemolymph (CHL). Then, the electrocatalytic stability of the AuNP-modified electrode was compared with an enzymatic electrode. Furthermore, a glucose biofuel cell consisting of the AuNP-modified electrode and a bilirubin oxidase-modified electrode was constructed; the respective power densities obtained from 100 mM glucose solution and CHL were 22.4 and 15.1 μW/cm², respectively. It is concluded that AuNPs are a useful catalyst for living batteries.