Optimizing the synthesis of red- and near-infrared CuInS2 and AgInS2 semiconductor nanocrystals for bioimaging

Abstract

This work reports the study of optimization of the reaction parameters on the synthesis of high quality CuInS2 and AgInS2 nanocrystals for bioimaging applications. The concentration of reaction precursors (e.g. Ag, Cu, In and S) plays a key role in determining the emission profile of these ternary quantum dots (QDs). By carefully varying the precursor compositions, the emission of QD can be tuned from red to near infrared (NIR) region. Taking the advantages of NIR emission, which possesses minimal absorption in biological tissues, we have also prepared water-dispersible CuInS2/ZnS and AgInS2/ZnS nanocrystals and demonstrated the high biocompatibility for both deep tissue penetration and tumor targeting. The QDs were stabilized in Pluronic F127 block copolymer micelles, offering us optically and colloidally stable contrast agents for in vitro and in vivo imaging. Two-photon excitation of QD has also been demonstrated, accomplishing a NIR-to-NIR transaction. This study devotes the key steps in promoting the use of ternary QDs as low-toxic, photostable, and cadmium-free semiconductor nanocrystal formulation for multiple imaging applications.

Heavy Metal Free Nanocrystals with Near Infrared Emission Applying in Luminescent Solar Concentrator

“…The QY was calculated by the formula QY = N emit / N abs as described in the experimental section, where N emit stands for the emitted photons from the NCs and N abs for the absorbed photons by the NCs. The obtained QY value was higher than that of I‐III‐VI NCs in the literature at longer emission wavelength range …”

Micelle-Encapsulated Quantum Dot-Porphyrin Assemblies as in Vivo Two-Photon Oxygen Sensors

“…Whereas the vast majority of synthetic procedures for micelle formation involve heating and evaporation of an organic solvent 39,41,43,44,50 or dissolution of an organic film in aqueous media or a similar method of phase transfer, 40,42,45,46,49,51,52 sonication offers an alternative method to assemble micelles. In contrast to other protocols, 47 we were able to rapidly (~5 min) and facilely produce micelle nanosensors of a consistent size by conducting sonication at room temperature.…”

Photocatalytic activity of CuInS2 nanoparticles synthesized via a simple and rapid microwave heating process

“…Copper indium sulfide (CuInS 2 ) is an interesting ternary metal sulfide that has a wide range of potential applications including photocatalysis [14][15][16][17][18], in photodetectors [19], bioimaging [20,21] and in solar cells [22,23]. Its conduction band is constructed from 5s orbital of In and its valence band consists of 3p orbitals of S [12]; thereby, a narrower band gap energy (1.53 eV for the bulk) can be achieved.…”