Hollow spherical nanostructured polydiphenylamine for direct electrochemistry and glucose biosensor

Nanostructured, hollow spheres of polydiphenylamine (HS-PDPA) are prepared through a “soft template assisted self-assembly” approach. An enzymatic glucose biosensor is fabricated through immobilizing glucose oxidase (GOx) into HS-PDPA matrix. The HS-PDPA–GOx electrode exhibits a pair of well-defined reversible redox peaks with a fast heterogeneous electron transfer rate. At an applied potential of +0.65 V, HS-PDPA–GOx electrode possesses high sensitivity (1.77 μA mM−1 cm−2), stability and reproducibility towards glucose. The amperometric current response of HS-PDPA–GOx to glucose is linear in the concentration range between 1 and 28 mM with a detection limit of 0.05 mM (S/N = 3). Also, HS-PDPA–GOx electrode shows high selectivity towards glucose in the presence of ascorbic acid, uric acid and acetaminophen at their maximum physiological concentrations.