Preparation and characterization of surface-modified semiconductor quantum dot

Abstract

Semiconductor quantum dots (QDs) are tiny light-emitting particles on the nanometer scale, and are emerging as a new class of fluorescent labels for biology and medicine. In comparison with organic dyes and fluorescent proteins, they have unique optical and electronic properties, with size-tunable light emission, superior signal brightness, resistance to photobleaching, and broad absorption spectra for simultaneous excitation of multiple fluorescence colors. We described the preparation and characterization of various surface coated luminescent semiconductor CdTe/CdS QDs for biological labeling. This study demonstrates the cytotoxicity and cellular uptake of all six surface-modified QDs. QD-surface modifications do play a significant role in cell cytotoxicity. In addition, increasing cytotoxicity with higher QD concentration for various surface coated QDs was observed. By demonstrating how nanoparticle surface coatings can influence cell toxicity, these results serve to suggest an additional factor to be considered in the design of biocompatible nanomaterials for future biological applications.