MoS2 / WS2 Nanosheets and Quantum Dots for Sensing Hemin and Fabrication of Self-Powered Photodetectors

In this study, it was found that transition metal dichalcogenide (TMDC)-based nanosheets (NSs) and quantum dots (QDs) provide a versatile platform for designing chemosensors and photodetectors. As proof-of-concept, its multifunctionality was demonstrated by preparing MoS2 and WS2 NSs and QDs by the probe sonication method that works as a fluorescence quenching indicator for hemin, and its combination with hemin are efficient photoactive material for fabricating self-powered photodetectors. For instance, at 23.8 μM concentration of hemin, the quenching efficiencies were observed to be 74, 93, 91, and 94% for MoS2 NSs, MoS2 QDs, WS2 NSs, and WS2 QDs, respectively. The sensing process is selective and applicable to real samples. In addition, the combination of MoS2 and WS2 nanomaterials with hemin collected from the sensing experiments was utilized for facile fabrication of photodetectors that exhibits responsivities of 0.95 and 2641 AW–1cm–2 at 0 V for MoS2 QDs/hemin and WS2 QDs/hemin, respectively. The devices show high detectivities of 5.99 × 1013 and 1.87 × 1014 Jones. The parameters are significant at 0 V, and hence, the devices possess signature characteristics of self-powered photodetectors. The working mechanism for both sensing and photodetection was found to be due to fluorescence resonance energy transfer and electrostatic interaction between the nanomaterials and hemin. The idea of using the resultant solution from the sensing experiments for device fabrication and the findings were not reported earlier. Therefore, it will help in developing cost-effective platforms for sensing different components with biological importance, as well as in fabricating energy efficient photodetectors.