铂溶胶修饰电极对鲁米诺电化学发光的增敏作用

Sensitization of the Electrochemiluminescence of Luminol from Platinum Sol Modified Electrode

用化学还原法制备了纳米铂溶胶,透射电鏡显示其粒径约为5 nm,经过电化学沉积可将铂溶胶修饰于铂盘电极上。在中性介质中,铂溶胶修饰电极对溶液中鲁米诺的电化学发光具有明显的增敏作用,且具有较好的稳定性。维生素C对此增敏的电化学发光有强烈的猝灭作用。因此,利用该修饰电极可测定痕量维生素C。灵敏度极高,检出限为2.0×10-13mol/L,并实现了片剂的检测,方法准确、可靠。

The platinum hydrosol was prepared by chemical reduction. The average dimension of the nanoparticles is approximately five nanometers in diameter that was estimated from transmission electron microscopic image. These particles were then modified on a Pt disk electrode during cyclic voltammetric process. In the neutral medium （ pH = 7.0 ）, the Pt nanoparticle modified electrode sensitized the electrochemiluminescence （ECL） of luminol. The sensitizing efficiency reached as high as one order of magnitude and has excellent stability and reproducibility. Furthermore, some reductive molecule such as vitamin C （Vc） strongly quenched the ECL, it providedes a new approach to determine the Vc with detection limit of 2.0 × 10^-13 mol/L.