The electrocatalysis of Ag/Ni bimetallic alloys to glucose oxidation was studied. It was found that the presence of Ag and Ni in the alloys facilitates each other's electrocatalysis toward glucose oxidation, exhibiting an interesting synergistic effect. At about 0.7 V vs SCE, the electrocatalysis of Ag toward glucose oxidation was enhanced by Ni. However, it's very difficult to obtain stable response signals at this potential although a relatively large current response to glucose was observed. Similarly, the presence of Ag improved the Ni(OH) 2 /NiOOH mediated electrocatalytic oxidation of glucose at 0.45 V. By contrast, the Ag/Ni-deposited electrode responded rapidly to the changes of glucose concentration, producing stable signals within 4 s. Two linear ranges were identified with one at low glucose levels from 1 to 9.89 μM and the other at high glucose concentrations from 19.68 to 106.89 μM. The detection limit of the electrode is 0.49 μM. This study shows the potential to develop glucose based sensors or fuel cells.

Metallic Bi and Ni were co‐deposited onto the surface of glass carbon electrode (GCE) from the electrolyte solution containing their respective nitrate to fabricate a Bi/Ni alloy modified GCE (Bi/Ni‐GCE). The purpose is to study the influence of Bi3+ on the deposition of Ni and that of deposited Bi on the electrocatalytic performance of Ni to glucose in alkali solution. The results show that both redox signal of Ni(OH)2/NiOOH and Ni(OH)2/NiOOH mediated electrocatalysis to glucose is remarkably increased in the presence of Bi. It seems that there is a synergistic effect between Bi and Ni on each other’s redox electrochemistry. It’s possible that the firstly deposited Bi on GCE surface helps to the following nucleation and growth of Ni, leading to the deposition of more metallic Ni on GCE surface. An extremely attractive feature of Bi/Ni‐GCE is reflected by the fast response time to the electrocatalytic oxidation of glucose. The electrode nearly responses immediately after glucose is added and it reaches a steady‐state level within only 2 seconds, demonstrating a good electrocatalytic property of Bi/Ni‐GCE. The calibration plot is linear over the wide concentration range of 0–5.8 mM with a sensitivity of 33.96 µA/mM and a correlation coefficient of 0.9985. The detection limit of the glucose was found to be 0.59 µM at a signal‐to‐noise ratio of 3. The fabricated Bi/Ni‐GCE was successfully employed to analyze the glucose level in blood samples, exhibiting high accuracy, strong resistance against inference and good reliability in the practical applications.

A simple strategy for the preparation of a Ni(OH)2 nanoparticle film is described. Ni(OH)2 nanoparticles were synthesized in an aqueous solution of Ni2+ and tert-butylamine in the presence of small amounts of toluene, which induced the nanoparticles to assemble a thin film on the aqueous surface. The obtained Ni(OH)2 nanoparticle film was easily transferred onto the electrode surfaces and exhibited stable electrochemical performance. The electrochemical behavior of various small biomolecules, including cysteine, homocysteine, glutathione, histidine, glycine, cystine, methionine, lysine, aspartic acid, glutamic acid, phenylalanine, ascorbic acid, uric acid and dopamine, were studied at the Ni(OH)2 nanoparticle-film-modified electrode. The Ni(OH)2 nanoparticle film exhibits excellent direct, unmediated electrocatalysis toward the oxidation of cysteine, homocysteine and ascorbic acid in a pH 7.4 buffer solution with a low onset potential and a high oxidation signal. This behavior differs from many reports in which small organic molecules are electrocatalyzed indirectly by the Ni(OH)2/NiOOH redox couple in a strongly alkaline solution.