Conductive Diamond Powder Ink as a Functional Electrode Material

Abstract

Conductive boron-doped diamond powder (BDDP) was prepared by the deposition of a BDD layer on insulating diamond powder. An ink containing BDDP and a binder was used for fabrication of screen-printed diamond electrodes as an application of the BDDP ink to functional electrode material. The BDDP-printed electrodes were found to exhibit low background current, leading to larger signal-to-background (S/B) ratios than those of conventional carbon-printed electrodes that are used for disposable electrochemical sensors. A glucose sensor was fabricated by coating an immobilized glucose oxidase film onto a cobalt phthalocyanine/BDDP-printed electrode, and was found to exhibit excellent glucose detection, especially at low concentrations, and a stable baseline current. In addition, a BDDP-printed electrode fabricated using an ink with a large binder/BDDP ratio exhibited highly sensitive electrochemical detection based on the random microelectrode array effect. Thus, BDDP-printed electrodes show enormous potential as disposable and highly sensitive electrochemical sensors.