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The hot injection synthesis of nanomaterials is a highly diverse and fundamental field of chemical research, which has shown much success in the bottom up approach to nanomaterial design. Here we report a synthetic strategy for the production of anisotropic metal chalcogenide nanomaterials of different compositions and shapes, using an optimised hot injection approach. Its unique advantage compared to other hot injection routes is that it employs one chemical to act as many agents: high boiling point, viscous solvent, reducing agent, and surface coordinating ligand. It has been employed to produce a range of nanomaterials, such as CuS, Bi2S3, Cu2-xSe, FeSe2, and Bi4Se3, among others, with various structures including nanoplates and nanosheets. Overall, this article will highlight the excellent versatility of the method, which can be tuned to produce many different materials and shapes. In addition, due to the nature of the synthesis, 2D nanomaterial products are produced as monolayers without the need for exfoliation; a significant achievement towards future development of these materials.
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Chirality strongly influences many biological properties of materials, such as cell accumulation, enzymatic activity, and toxicity. In the past decade, it has been shown that quantum dots (QDs), fluorescent semiconductor nanoparticles with unique optical properties, can demonstrate optical activity due to chiral ligands bound on their surface. Optically active QDs could find potential applications in biomedical research, therapy, and diagnostics. Consequently, it is very important to investigate the interaction of QDs capped with chiral ligands with living cells. The aim of our study was to investigate the influence of the induced chirality of Mn-doped ZnS QDs on the viability of A549 cells. These QDs were stabilized with D- and L-cysteine using a ligand exchange technique. The optical properties of QDs were studied using UV-Vis, photoluminescence (PL), and circular dichroism (CD) spectroscopy. The cytotoxicity of QDs was investigated by high content screening analysis. It was found that QDs stabilized by opposite ligand enantiomers, had identical PL and UV-Vis spectra and mirror-imaged CD spectra, but displayed different cytotoxicity: QDs capped with D-cysteine had greater cytotoxicity than L-cysteine capped QDs.
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Here we report a new low temperature dry ice carbonation approach for the synthesis of carbonate-based nano- and micro-particulate materials, which enables the preparation of monodispersed calcium carbonate nanoparticles and microspheres with very high purity phases.
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In this review we present new concepts and recent progress in the application of semiconductor quantum dots (QD) as labels in two important areas of biology, bioimaging and biosensing. We analyze the biologically relevant properties of QDs focusing on the following topics: QD surface treatment and stability, labeling of cellular structures and receptors with QDs, incorporation of QDs in living cells, cytotoxicity of QDs and influence of the biological environment on the biological and optical properties of QDs. Initially, we consider utilization of QDs as agents in high-resolution bioimaging techniques that can provide information at the molecular levels. The diverse range of modern live-cell QD-based imaging techniques with resolution far beyond the diffraction limit of light is examined. In each technique, we discuss the pros and cons of QD use and deliberate how QDs can be further engineered to facilitate their application in the respective imaging techniques and to produce significant improvements in resolution. Then we review QD-based point-of-care bioassays, bioprobes, and biosensors designed in different formats ranging from analytic biochemistry assays and ELISA, to novel point-of-care smartphone integrated QD-based biotests. Here, a wide range of QD-based fluorescence bioassays with optical transduction, elecrochemiluminescence and photoelectrochemical assays are discussed. Finally, this review provides an analysis of the prospects of application of QDs in selected important areas of biology.
RESUMEN
The influence of the chirality of semiconductor nanocrystals, CdSe/ZnS quantum dots (QDs) capped with L- and D-cysteine, on the efficiency of their uptake by living Ehrlich Ascite carcinoma cells is studied by spectral- and time-resolved fluorescence microspectroscopy. We report an evident enantioselective process where cellular uptake of the L-Cys QDs is almost twice as effective as that of the D-Cys QDs. This finding paves the way for the creation of novel approaches to control the biological properties and behavior of nanomaterials in living cells.