Surfactant-free synthesis of fluorescent platinum nanoclusters using HEPES buffer for hypochlorous acid sensing and imaging.

A surfactant-free synthesis of noble-metal nanoclusters (NMNCs) with specific function has recently remained more attractive and superior in bio-applications. Herein, by employing the weak reducibility of non-toxic HEPES, we prepared novel water-soluble fluorescent HEPES@Pt NCs by a simple surfactant-free synthesis strategy for hypochlorous acid (HClO) sensing. The as-prepared Pt NCs featured ultra-small size (∼2 nm), bright blue fluorescence, high stability and biocompatibility, and the fluorescence of the Pt NC nanoprobe can be specifically quenched with hypochlorous acid by a static quenching process.

Surfactant-free synthesis of porous Au by a urea complex.

We report a facile surfactant-free synthetic method to obtain porous and hollow Au nanoparticles using only urea and HAuCl·4HO as precursors at 200 °C. The formation mechanism was investigated through X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. Moreover, the prepared Au nanocrystals present superior catalytic performance for the reduction of 4-nitrophenol in comparison with solid Au nanoparticles.