Synthesis and characterization of alanine-capped water soluble copper sulphide quantum dots

Copper sulphide has interesting chemistry as it is capable of forming various stoichiometries and couple to that, it has excellent electrical, optical and magnetic properties. Its optical and magnetic attributes renders it a suitable candidate in a nano-regime for biological applications. We therefore report on the synthesis of single-phase, water soluble CuS nanoparticles using a simple colloidal route with alanine as the stabilizing and compatibility ligand. We further report on the optical and morphological properties of CuS nanoparticles as a function of temperature. The employed synthetic method successfully yielded water soluble CuS nanoparticles with a single crystal phase. The binding mode of alanine on the surface of the nanoparticles was shown to be pH dependent. The temperature had an effect on both the optical and morphological properties of the particle. The highest synthetic temperature (100 degrees C) resulted in particles with properties superior to the ones synthesized at lower temperatures and the surface coverage of the nanoparticles with alanine improved with increasing temperature. (C) 2012 Elsevier B.V. All rights reserved.