Porous gold cluster film prepared from Au@BSA microspheres for electrochemical nonenzymatic glucose sensor

To obtain hierarchically porous gold-cluster film as the direct electrochemical sensing interface for nonenzymatic glucose detection, a facile, cost-effective, environmentally friendly and bottom-up approach was developed by calcination of Au@BSA microspheres. The fabricated gold-cluster film was composed of the network structure interconnected with Au particles and the disordered 3D hierarchical pores. Due to large surface area, high electroconductivity and excellent electrocatalysis towards glucose oxidation, the as-prepared sensor showed high current response so that the glucose determination could be carried out at a less positive potential where common interferents (ascorbic acid, acetamidophenol and uric acid) were not oxidized. Importantly, 0.15 M chloride ions (Cl−) had no poisoning effect on the gold-cluster electrode. Meanwhile, the sensor also exhibited a rapid response (5 s), high sensitivity (10.76 μA mM−1 cm−2), a low limit of detection (1 μM), a wide and useful linear range (0.01 − 10 mM), good operational stability and storage stability. This work not only demonstrated an excellent direct electrochemical sensing interface for nonenzymatic detection of glucose, but also would extend to other noble metal films and metal oxide films as various electrodes and electrochemical interface.