Rectified quantized charging of gold nanoparticle self - assembled monolayers by arenedithiol linkages

Gold nanoparticle self-assembled monolayers were fabricated by a sequential anchoring mechanism with rigid arenedithiol chemical linkers. These particle surface assemblies exhibited well-defined quantized capacitance characters in aqueous solutions, and more importantly, in aqueous solutions, the voltammetric responses were rectified in the presence of hydrophobic anions, which was interpreted on the basis of a Randle's equivalent circuit where the particleion pairing formation led to the manipulation of electrode interfacial double-layer capacitance. The effective nanoparticle capacitances evaluated from the voltammetric measurements were consistent with those with the particles immobilized onto electrode surfaces by alkanedithiols. In addition, the nanoparticle electron-transfer kinetics was investigated by AC voltammetry and the rate constants were generally found of the order of 1 O , at least an order of magnitude greater than those with saturated alkyl spacers.