Facile fabrication of 3D honeycomb-like porous GaN photoanode for reliable and sensitive photoelectrochemical detection of glucose

Abstract

A novel photoelectrochemical glucose sensor was constructed based on three-dimensional (3D) porous GaN photoanode fabricated via wet etching of as-grown GaN epitaxial wafer. The increased photocurrents indicated glucose can be photooxidized by 3D porous GaN in both neutral and alkaline electrolytes. In neutral electrolyte, the detection range and sensitivity were 100 µM to 3.6 mM and 40.14 µA mM−1 cm−2, respectively. In alkaline electrolyte, the detection range was 1 µM to 6.66 mM, and the sensitivities were 631.9 µA mM−1 cm−2 in the range of 1–161 µM and 60.03 µA mM−1 cm−2 in the range of 161 µM to 6.66 mM. Moreover, 3D porous GaN exhibited favorable reproducibility, good selectivity and satisfied stability toward glucose detection. In addition, this sensor can detect glucose in human serum samples, demonstrating the good practicability of 3D porous GaN.