Synthesis and Applications of Dendrimer-Encapsulated Pt Nanoparticles in Chemical Sensors

摘要

Synthesis of nanoparticles having well-defined small sizes especially less than ～3 nm has been in the forefront of research attention in diverse fields including biological and chemical sensors because of unique features of such very small particles. Synthesis and characterization of such tiny particles still remains challenging due to the extremely small dimension of the particles, too. Here, I present the synthesis of ultra-small Pt nanoparticles having different but uniform sizes using dendrimers as a molecular template, which is usually denominated as dendrimer-encapsulated nanoparticles (DENs). Specifically, I present a new synthesis strategy of Pt DENs to expand the applicable number of Pt atoms in Pt DENs by utilizing repetitively coupled chemical reduction and galvanic exchange reactions. The applications of Pt DENs is also discussed in chemical sensors. For example, I present the modification of indium tin oxide (ITO) with Pt DENs to provide enhanced stable electrochemiluminescence (ECL) of Ru(bpy)_3~(2+)/tripropylamine while preserving optical transparency of ITO for sensitive ECL-based analyses.