纳米孔金膜电极的制备及应用

Synthesis of Nanoporous Gold Electrode and Its Application in Electrochemical Sensor

在氨性溶液中,以HAuCl4和AgNO3为原料,采用电化学还原法直接在氧化铟锡(ITO)导电玻璃基底上沉积金银合金膜,然后用HClO4溶液去合金化,较活泼的金属银溶解,从而制备了高表面积的纳米孔金膜修饰电极,并对修饰电极进行了表征。纳米孔金膜的表面积可通过调控电解的条件来控制,所制备的纳米孔金膜电极可采用L-半胱胺酸自组装法进一步功能化,并应用于高灵敏和高选择性测定Cu2+。在优化实验条件下,Cu2+的吸附时间为5 min,采用线性扫描伏安法测定Cu2+浓度的线性范围为0.05～4.0μmol/L,检出限为0.03μmol/L,对1μmol/L Cu2+平行测定9次,其相对标准偏差为4.3%。本方法用于环境水样中Cu2+的测定,结果令人满意。

In ammonia solution, binary gold-silver alloy films were directly deposited onto indium tin oxide （ITO） substrate surfaces using electrochemical method from chloroauric acid and silver nitrate. Then high- surface-area nanoporous gold （NPG） film modified electrodes were fabricated by chemical dealloying of the less noble component silver from the surface. The modified electrodes were characterized. The electrode can be successfully functionalized with self-assembled monolayers of L-cysteine, which can be applied to the sensitive and selective determination of Cu2~. Under the optimal conditions and 5 min of absorption time for Cu2＋ ions, the cathodic current was linear proportional with Cu2＋ concentration from 0.05 to 4 p.mol/L with a detection limit of 0.03μmol/L. The relative standard deviation was 4.3% for 1 p.mol/L Cu2＋ solution. The established method was successfully applied for the determination of Cu2＋ in water sample of environment.