利用羧基对金属离子的络合作用在电极表面原位制备金属粒子用于电催化过氧化氢(H2O2).首先在电极表面电沉积聚丙烯酸,然后化学吸附铜离子,再用水合肼将其还原成零价铜.铜粒子簇均匀分散在聚丙烯酸网络中,其尺寸可通过吸附铜离子的数量和吸附-还原次数来控制.由于铜微粒的电催化作用,该修饰电极对H2O2表现出了良好的电流响应.运用该方法可以在电极表面制备多种金属微粒,并且聚丙烯酸的自由羧基可以与氨基反应,从而可共价固定带氨基的酶和抗体,有望构建多种新型的化学和生物传感器.
The complexation of carboxyl groups to metal ions was exploited to in situ prepare metal particles on the electrode surface for electrocatalysis of hydrogen peroxide (H2O2). Poly(acrylic acid) (PAA) was first electrodeposited onto a gold electrode. Then copper ions were chemically adsorbed within the PAA network, and subsequently reduced by hydrazine hydrate to yield zerovalent copper. The resultant Cu clusters were uniformly dispersed in the PAA network and their size and density could be easily controlled through controlling the amount of copper ions in the film and the loading-reduction cycles. Thus modified electrode showed good current response to H2O2 due to the catalytic activity of copper particles. Various metal catalysts can be prepared on the electrode surface by the same method. Moreover, PAA can covalently immobilize enzyme and antibody by bonding between amino groups of the biomolecules and free carboxyl groups of PAA, therefore, a variety of new chemo- and bio-sensors could be constructed.