纳米Pt-Au合金修饰电极对鲁米诺电化学发光的增敏研究

用化学还原法制备了不同比例及不同粒径的纳米Au-Pt合金，并用UV-Vis、TEM、激光粒径、XRD等方法进行了表征，确认所合成物质确系双金属合金纳米粒子而非两种金属纳米粒子的混合物，通过改变合成方法和条件，可以得到一系列不同含量比和粒径，粒径范围在4.025～92.33 nm之间。采用电化学沉积法可将所制备合金修饰到铂盘电极上，在碱性介质(pH 12)中，随着合金比例的改变和合金粒径的减小，鲁米诺的电化学发光强度显著增强，当合金中Pt∶Au=6∶1，粒子粒径为最小时，所获得修饰电极上鲁米诺的电化学发光强度较裸电极增强近1个数量级。

Studies on Sensitization for Electrochemiluminescence of Luminol with Platinum-Gold Bimetallic Nanoparticles Modified Electrode

The present paper reports the researches on sensitization of nano-bimetalic material for the electrochemiluminescence (ECL) of luminol. The platinum-gold bimetallic nanoparticles with different component ratio and size were prepared by chemical reduction. The analytical methods such as UV-Vis spectra, TEM and XRD were applied to characterize the properties of the nanoparticles. The information obtained from these methods revealed that the prepared bimetallic nanoparticles were truly of alloy structure and absolutely not the mixture of two kinds of metallic nanoparticles. The components of the nanoparticles could be regulated for a series of Pt/Au ratios and the diameters determined by laser-granulometer. In alkaline medium of pH 12.0, the bimetallic Pt-Au nanoparticle modified electrode sensitized the electrochemiluminescence of luminol. The sensitization efficiency reached as high as one order of magnitude with the 6∶1 of Pt/Au ratio. The specific surface area of nanoparticles would be larger as the size diminishes, resulting in a higher surface activity, so the smallest size of nanoparticles led to the highest efficiency.