High-sensitivity non-enzymatic glucose biosensor based on Cu(OH) ₂ nanoflower electrode covered with boron-doped nanocrystalline diamond layer

A non-enzymatic biosensor was developed using boron-doped nanocrystalline diamond (BDND) based on a Cu electrode with Cu(OH) ₂ dendritic architecture. The Cu(OH) ₂ nanoflower electrode was covered with a BDND layer using an electrostatic self-assembly seeding method with nanodiamond particles and hot-filament chemical vapor deposition. X-ray diffraction and Raman spectral analysis confirmed that the BDND nanoflower electrode was synthesized onto Cu(OH) ₂ nanoflowers. Field-emission scanning electron microscope images showed that the fabricated electrodes were nanoflowers possessing large surface areas. From cyclic voltammetry, the peak currents of an BDND/Cu(OH) ₂/Cu electrode was about 7, 6.2, and 5.9 times higher than that of the Cu foil, Cu(OH) ₂/Cu, and BDND/Cu electrodes, respectively. A biosensor based on BDND/Cu(OH) ₂/Cu exhibited excellent performance for glucose detection, and it had a linear detection range of 0 to 6 mM, a correlation coefficient of 0.9994, a low detection limit of 9 μM, and a high sensitivity of 2.1592 mA mM ^{- 1} cm ^{- 1}.