Non-Enzymatic Glucose Detection Using Free Standing Hollow Boron-Doped Diamond Nanorod Electrodes

Abstract

A free standing boron-doped diamond hollow nanorods (BDD HRs) electrode was synthesized as an active sensing platform for detection of glucose. Tungsten oxide nanorods (WOx NRs) were employed as a removable framework to leave free standind BDD HRs. The morphology of WOx NRs was optimized by two step growth to have most faborable sensing property. The BDD layer was deposited on the surface of WOx NRs to build up BDD-WOx core-shell nanostructures. After the deposition of BDD, the WOx NRs core was fully dissolved out by electrochemical oxidation process, and the BDD HRs structure was obtained. The morphology and composition of the BDD HRs electrodes were characterized by field-emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy and X-ray diffractometer, respectively. And their electrochemical properties were analyzed by cyclic voltammetry and electrochemical impedance spectroscopy. Compared with a planar BDD electrode, the BDD HRs electrodes have enhanced sensing performances - higher sensitivity (349.7 μA/mM·cm2), lower detection limit (0.066 μM), fast response time (< 5 s) and wider linear range (0.00112 ∼ 0.067 mM). It was attributed to the unique property of the BDD HRs such as large surface area, effective glucose diffusion/migration and highly effective direct electron transfer.