Application of a Cu-Co alloy dendrite on glucose and hydrogen peroxide sensors

摘要

A Cu-Co alloy dendrite with a hierarchical nanostructure was electrochemically synthesized, and it characterized using scanning electron microscope, energy dispersive X-ray spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray diffractometry, X-ray photoelectron spectroscopy, coulometry, and cyclic voltammetry. The catalytic characteristics of the dendrite were examined for its use with highly sensitive glucose and H_2O_2 sensors. The TOF-SIMS image shows that the Cu-Co alloy dendrite grew homogeneously in a hierarchical structure. The Co~(2+) ions that formed on the alloy dendrite mainly contributed to glucose oxidation, and the Cu~+ ion cooperated synergically with the Co~(2+) ion. However, Co~(3+) was mainly involved in the reduction of H_2O_2, while the reduction with Cu~(2+) ion cooperated synergically. The major oxidation products of glucose on the dendrite was confirmed to be formate (12-electron oxidation product) through coulometry and product analysis with a HPLC-MS analyzer. The linear calibration plots for the glucose and H_2O_2 analyses were obtained between 0.5 μM to 14.0mM (detection limit was 0.10±0.05 μM) and 1.0 μM to 11.0mM (detection limit was 0.75 ± 0.15 μM), respectively. The performance of the final sensor was evaluated with a human blood sample.