A convenient and simple strategy for preparing water soluble, photoluminescent functionalized silica nanoparticles (M-dots) in the absence of fluorophores or metal doping is demonstrated. These M-dots can be used for bioimaging using one and two-photon microscopy. Because of their high photostability, low toxicity and high biocompatibility compared with Lumidot™ CdSe/ZnS quantum dots, functiona...

INTRODUCTION Using colloidal CdSe/ZnS quantum dots in the submicron-sized silicon disk cavity, we have developed a visible wavelength nanodisk laser that operates under extremely low threshold power at room temperature. METHODS Time-resolved photoluminescence (PL) of QDs; nanodisk by e-beam lithography. RESULTS Observation of lasing action at 594 nm wavelength for quantum dots on a nanodisk...

Time-resolved single-nanoparticle spectroscopy has been carried out to examine the luminescence characteristics of individual CdSe/ZnS core/shell quantum dots. In particular, the possible correlations between emission intensity, lifetime, spectrum, and polarization fluctuations have been investigated. The emission polarization was found to be correlated with the luminescence intensity in a nonl...

Alkaline phosphatase (ALP) activity was detected using bovine serum albumin (BSA)-functionalized manganese-doped zinc sulfide (Mn–ZnS) quantum dots (QDs), and the phosphate substrate vitamin-B 6 cofactor pyridoxal 5′-phosphate (PLP).

In this work, nano-photocatalysts based on ZnS quantum dots (QD) functionalized by chitosan were developed using “green” colloidal chemical process in aqueous media at room temperature. The ZnS/chitosan nano-photocatalysts were extensively characterized and the results demonstrated that chitosan was an effective capping ligand for the direct production of water-soluble ZnS QDs with average nano...

Using transmittance electron microscopy, fluorescence and polarizing optical microscopy, optical spectroscopy, and fluorescent correlation spectroscopy, it was shown that CdSe/ZnS quantum dots coated with a specifically designed surfactant were readily dispersed in nematic liquid crystal (LC) to form stable colloids. The mixture of an alkyl phosphonate and a dendritic surfactant, where the cons...

The photoluminescence dynamics of colloidal CdSe/ZnS/streptavidin quantum dots were studied using time-resolved single-molecule spectroscopy. Statistical tests of the photon-counting data suggested that the simple "on/off" discrete state model is inconsistent with experimental results. Instead, a continuous emission state distribution model was found to be more appropriate. Autocorrelation anal...

BACKGROUND Currently, graphene oxide has attracted growing attention as a drug delivery system due to its unique characteristics. Furthermore, utilization of microRNAs as biomarkers and therapeutic strategies would be particularly attractive because of their biological mechanisms and relatively low toxicity. Therefore, we have developed functionalized nanocompounds consisted of graphene oxide, ...

Zinc oxide nanorod arrays (ZnO NRs) were grown on the ZnO seed layers via an aqueous solution using hydrothermal method and their photovoltaic properties were investigated. It was found that the growth period of 20 minutes is the optimum condition for ZnO nanorods growth, the cell containing these nanorods was considered as a reference cell. In order to further increase the cell performance, Zn...

Carboxylate-terminated and dopamine-conjugated CdSe-ZnS quantum dots (QDs) are imaged in living fibroblasts using fluorescence lifetime imaging microscopy. Changes in lifetime are observed as the QDs are processed in the cells, and are consistent with lifetime measurements in bulk solution using buffers compositions that correspond to different cellular regions.