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

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 H2O2 sensors. The TOF-SIMS image shows that the Cu-Co alloy dendrite grew homogeneously in a hierarchical structure. The Co2+ ions that formed on the alloy dendrite mainly contributed to glucose oxidation, and the Cu+ ion cooperated synergically with the Co2+ ion. However. Co3+ was mainly involved in the reduction of H2O2, while the reduction with Cu2+ 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 H2O2 analyses were obtained between 0.5 mu M to 14.0 mM (detection limit was 0.10 +/- 0.05 mu M) and 1.0 mu M to 11.0 mM (detection limit was 0.75 +/- 0.15 mu M), respectively. The performance of the final sensor was evaluated with a human blood sample. (C) 2011 Elsevier Ltd. All rights reserved.