Development of Self-Doped Monolayered 2D MoS2 for Enhanced Photoresponsivity.

Transition metal dichalcogenides (TMDs) exist in two distinct phases: the thermodynamically stable trigonal prismatic (2H) and the metastable octahedral (1T) phase. Phase engineering has emerged as a potent technique for enhancing the performance of TMDs in optoelectronics applications. Nevertheless, understanding the mechanism of phase transition in TMDs and achieving large-area synthesis of phase-controlled TMDs continue to pose significant challenges. This study presents the synthesis of large-area monolayered 2H-MoS2 and mixed-phase 1T/2H-MoS2 by controlling the growth temperature in the chemical vapor deposition (CVD) method without use of a catalyst. The field-effect transistors (FETs) devices fabricated with 1T/2H-MoS2 mixed-phase show an on/off ratio of 107. Photo response devices fabricated with 1T/2H-MoS2 mixed-phase show ≈55 times enhancement in responsivity (from 0.32 to 17.4 A W-1) and 102 times increase in the detectivity (from 4.1 × 1010 to 2.48 × 1012 cm Hz W-1) compare to 2H-MoS2. Introducing the metallic 1T phase within the 2H phase contributes additional carriers to the material, which prevents the electron-hole recombination and thereby increases the carrier density in the 1T/2H-MoS2 mixed-phase in comparison to 2H-MoS2. This work provides insights into the self-doping effects of 1T phase in 2H MoS2, enabling the tuning of 2D TMDs properties for optoelectronic applications.

Arsenic album 30C exhibits crystalline nano structure of arsenic trioxide and modulates innate immune markers in murine macrophage cell lines.

Macrophages are associated with innate immune response and M1-polarized macrophages exhibit pro-inflammatory functions. Nanoparticles of natural or synthetic compounds are potential triggers of innate immunity. As2O3 is the major component of the homeopathic drug, Arsenic album 30C.This has been claimed to have immune-boosting activities, however, has not been validated experimentally. Here we elucidated the underlying mechanism of Ars. alb 30C-mediated immune priming in murine macrophage cell line. Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD) used for the structural analysis of the drug reveals the presence of crystalline As2O3 nanoparticles of cubic structure. Similarly, signatures of M1-macrophage polarization were observed by surface enhanced Raman scattering (SERS) in RAW 264.7 cells with concomitant over expression of M1 cell surface marker, CD80 and transcription factor, NF-κB, respectively. We also observed a significant increase in pro-inflammatory cytokines like iNOS, TNF-α, IL-6, and COX-2 expression with unaltered ROS and apoptosis in drug-treated cells. Enhanced expression of Toll-like receptors 3 and 7 were observed both in transcriptional and translational levels after the drug treatment. In sum, our findings for the first time indicated the presence of crystalline As2O3 cubic nanostructure in Ars. alb 30C which facilitates modulation of innate immunity by activating macrophage polarization.