Unique photoluminescence response of MoS2quantum dots over a wide range of As (III) in aqueous media

Recent progress in MoS2 nanostructures for biomedical applications: Experimental and computational approach

In the category of 2D materials, MoS2 a transition metal dichalcogenide, is a novel and intriguing class of materials with interesting physicochemical properties, explored in applications ranging from cutting-edge optoelectronic to the frontiers of biomedical and biotechnology. MoS2 nanostructures an alternative to heavy toxic metals exhibit biocompatibility, low toxicity and high stability, and high binding affinity to biomolecules. MoS2 nanostructures provide a lot of opportunities for the advancement of novel biosensing, nanodrug delivery system, electrochemical detection, bioimaging, and photothermal therapy. Much efforts have been made in recent years to improve their physiochemical properties by developing a better synthesis approach, surface functionalization, and biocompatibility for their safe use in the advancement of biomedical applications. The understanding of parameters involved during the development of nanostructures for their safe utilization in biomedical applications has been discussed. Computational studies are included in this article to understand better the properties of MoS2 and the mechanism involved in their interaction with biomolecules. As a result, we anticipate that this combined experimental and computational studies of MoS2 will inspire the development of nanostructures with smart drug delivery systems, and add value to the understanding of two-dimensional smart nano-carriers.

Polychromatic fluorescent MoS2 quantum dots: fabrication and off-on sensing for fluorine ions in water

Recently, MoS₂ quantum dots (QDs) have receive widespread attention as a promising luminescent material. However, so far, little effort has been made on the multicolor emission of MoS₂ QDs. Herein, an in situ iodine doping strategy is presented and used to synthesize tunable-photoluminescent (PL) MoS₂ QDs. By fine iodine doping, the PL of the MoS₂ QDs (I-MoS₂ QDs) can be tuned in the range from 423 nm to 529 nm, which exceeds the as-reported emission wavelength range. Studies using controlled experiments and density functional theory (DFT) reveal that the change in electronic state of MoS₂ QDs is responsible for the changing PL due to iodine doping. As-synthesized I-MoS₂ QDs combined with Fe³⁺ is developed as a "turn-off-on" fluorescence sensor for F^- ions in water. The fluorescence probe has a fine linear response to F^- ions in the concentration range of 2.5-80 μM, and the limit of detection is 1.4 μM (S/N = 3).