Developing molecular devices and electronics on diamond platform

Abstract

To utilize diamond as the superior platform for molecular devices, special surface modifications and chemistry are required to impart functional groups on the otherwise inert surface. Surface carboxylic acid groups were grafted through UV photochemical grafting of undecylenic acid on H-terminated diamond and biomolecules were subsequently coupled for impedimetric biosensing application. Diazonium chemistry to graft arylhalide or arylboronic ester was employed as synthon for subsequent surface Suzuki coupling to target aromatic molecules. This novel method provides direct wiring of conjugated molecules on diamond which is evident in coupling of light-harvesting molecules for photoelectrochemistry. More importantly, the diamond-based molecular photoconversion device was found to exhibit higher efficiency and better stability compared to typical transparent conducting electrodes. Furthermore, we have successfully immobilized phosphotungstic acid (PTA), a polyoxometalate (POM), on the surface of boron-doped diamond (BDD) surface through electrostatic self-assembly of PTA on pyridinium dye-functionalized-BDD.