Zelin Li

Nonenzymatic amperometric response of glucose on a nanoporous gold film electrode fabricated by a rapid and simple electrochemical method

An enzyme-free amperometric method was established for glucose detection using a nanoporous gold film (NPGF) electrode prepared by a rapid one-step anodic potential step method within 5 min. The prepared NPGF had an extremely high roughness and was characterized by scanning electron microscopy (SEM) and cyclic voltammetry. Electrochemical responses of the as-prepared NPGF to glucose in 0.1M phosphate buffer solution (PBS, pH 7.4) with or without Cl(-) were discussed. In amperometric studies carried out at -0.15 V in the absence of Cl(-), the NPGF electrode exhibited a high sensitivity of 232 μA mM(-1)cm(-2) and gave a linear range from 1mM up to 14 mM with a detection limit of 53.2 μM (with a signal-to-noise ratio of 3). In addition, the oxidation of ascorbic acid (AA) and uric acid (UA) can be completely eliminated at such a low applied potential. On the other hand, the quantification of glucose in 0.1M PBS (pH 7.4) containing 0.1M NaCl offered an extended linear range from 10 μM to 11 mM with a sensitivity of 66.0 μA mM(-1)cm(-2) and a low detection limit of 8.7 μM (signal-to-noise ratio of 3) at a detection potential of 0.2V.

In situ surface Raman study of the induced codeposition mechanism of Ni–Mo alloys

The induced codeposition of molybdenum with nickel on a Ni–Cu alloy electrode has been investigated by means of in situ surface Raman spectroscopy to obtain information about the codeposition mechanism during electrodeposition of Ni–Mo alloys. The experimental results show that, in the NiSO4-free solution, molybdate can only be reduced to a mixture of polyvalent molybdenum oxides and/or hydroxide, while, in the case where NiSO4 coexisted in the solution, molybdate is first reduced to Mo(IV) oxide, which, as an intermediate, subsequently is reduced to molybdenum in alloy under the catalysis of inducing nickel.