Excitation Wavelength Dependent Behavior Research Articles

77‐1: Invited Paper: The Colloidal Quantum Dot Based Color Conversion Layer for Micro LED Arrays

The advances of micro LEDs and colloidal quantum dots have provided a great platform for the next generation of micro displays. Although the illuminating efficiency of colloidal quantum dots is close to 100%, the patterning of these nanocrystals is still important and need to be developed. We use semiconductor grade fabrication to obtain small pixels smaller than 10 micrometers and a large scale formation of array. The photonic characterization reveals the conversion efficiency is 20% and the excitation wavelength dependent behavior is also probed. A 1300‐hour of vacuum storage test showed this type of color conversion layer is stable and the emission wavelength and linewidth are almost unchanged.

One-pot synthesis of fluorescent nitrogen-doped carbon dots with good biocompatibility for cell labeling.

Here we report an easy and economical hydrothermal carbonization approach to synthesize the fluorescent nitrogen-doped carbon dots (N-CDs) that was developed using citric acid and triethanolamine as the precursors. The synthesis conditions were optimized to obtain the N-CDs with superior fluorescence performances. The as-prepared N-CDs are monodispersed sphere nanoparticles with good water solubility, and exhibited strong fluorescence, favourable photostability and excitation wavelength-dependent behavior. Furthermore, the in vitro cytotoxicity and cellular labeling of N-CDs were investigated using the rat glomerular mesangial cells. The results showed the N-CDs have more inconspicuous cytotoxicity and better biosafety in comparison with ZnSe quantum dots, although both targeted the cells successfully. Considering their admirable photostability, low toxicity and good compatibility, the as-obtained N-CDs could have potential applications in biosensors, cellular imaging, and other fields.

Simple fabrication of eptifibatide stabilized gold nanoclusters with enhanced green fluorescence as biocompatible probe for in vitro cellular imaging

In this work, water-soluble highly fluorescent gold (Au) nanoclusters capped with eptifibatide (eptifibatide@Au NCs) were synthesized with sodium borohydride (NaBH4) as the reducing agent, in which sodium bromide (NaBr) was used as an excellent fluorescence sensitizer in the neutral media. The corresponding fluorescent intensity can enhance 3.37 times in comparison with that in the absence of NaBr, with the fluorescence quantum yield of 1.8%. Furthermore, the as-prepared fluorescent probe exhibits bright green fluorescence, high optical stability, excitation wavelength dependent behavior, good biocompatibility and low toxicity. Furthermore, the cell imaging experiments demonstrate that eptifibatide@Au NCs can stain the cell membrane and cytoplasm of HeLa and Chromaffin cells. These superior characteristics show their promising applications in cellular imaging and biological analysis.

Enhanced Raman Scattering as a Probe for 4-Mercaptopyridine Surface-modified Copper Oxide Nanocrystals

We report on the application of Raman scattering as a probe to study 4-mercaptopyridine (4-Mpy) surface-modified CuO nanocrystals. Enhanced Raman scattering from 4-Mpy adsorbed on CuO nanocrystals was observed. The Raman signals displayed 10(2) enhancement compared with those of 4-Mpy in solution. We compared the Raman spectra of 4-Mpy molecules adsorbed on CuO nanocrystals and Ag, Cu substrate. A particular feature of the semiconductor substrate that was different from the metal substrate was revealed. The excitation wavelength-dependent behavior was clearly observed.