[Syntheses and spectral studies of functionalized ZnS nanoparticles as fluorescence probes]

In this work, nano-ZnS has been successfully prepared. The nano-ZnS has also been modified with sodium mercaptoacetic acid. The functionalized nanoparticles are water-soluble and biocompatible. All the nanoparticles have been characterized by IR spectra, UV spectra, fluorescence spectra and TEM images. In comparison with single organic fluorophore, the nanoparticles probes are brighter and more photostable, and do not suffer from blinking. The nanoparticles have a narrow, tunable, symmetric emission spectrum and a broad, continuous excitation spectrum. They are also photochemically stable. Effects of proteins and nucleic acids on the UV spectra and fluorescence spectra of the functionalized ZnS have also been studied. The intensities of UV spectra and fluorescence spectra of the functionalized ZnS are enhanced by proteins, and, however, are quenched by nucleic acids. The functionalized colloidal solutions prepared are hopeful of use as fluorescence probes in biological staining and diagnostics.