Synthesis and characterization of a new water-soluble non-cytotoxic mito-tracker capped silicon quantum dot

Allyl triphenylphosphonium bromide based mito-tracker capped silicon quantum dot ( Mito-SiQDs ) has been synthesized through an inverse micelle process. It was then fully characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, dynamic light scattering techniques and X-ray photoelectron spectroscopic method. Energy dispersive X-ray spectroscopy analyses of the quantum dots confirm the presence of carbon, silicon, phosphorous and bromine atoms in Mito-SiQDs . Morphological study by transmission electron microscopy experiment showed the formation of the particles of size 11-12 nm of quantum dot dimension. The high negative zeta potential value of –23.7 mV calculated from dynamic light scattering study indicates the high stability of the circumvent agglomeration of Mito-SiQDs . The mito-tracker capped silicon quantum dot has blue emission at 400 nm wavelength upon excitation at 327 nm. Mito-SiQDs has not shown any significant cytotoxic effect with 10 to 50 μL/mL concentration on HeLa cell line for at least up to 12 h of its treatment. The Mito - SiQDs would be useful a possible fluorescent marker to visualize mitochondrial subcellular compartment in living cell through fluorescence imaging study.