Water-soluble VS2 quantum dots with unusual fluorescence for biosensing

Quantum dots (QDs) derived from two-dimensional transition metal dichalcogenides (TMDs) are emerging extraordinary zero-dimensional materials with interesting photoelectric properties and versatile applications in optoelectronics, imaging, sensing, catalysis, energy and so on. As a typical metallic member of TMDs, vanadium disulfide (VS2) is stimulating high expectation on the novel functional material. In this work, high-quality water-soluble VS2 quantum dots (QDs) with lateral size of similar to 3.3 nm is unprecedentedly achieved via a facile hydrothermal approach. The as-prepared VS2 QDs displays uniform distribution, high stability and unusual fluorescence (UV and NIR excitation), which has been demonstrated as a signal indicator for the first time to establish a "turn-on" sensing platform for biomolecules. Based on the efficient fluorescence resonance energy transfer from VS2 QDs to MnO2 nanosheets and the fast redox reaction between MnO2 and glutathione (GSH), the proposed sensor exhibits good assay performances including wide detection range, satisfying sensitivity and high selectivity for GSH under UV and NIR irradiation. The research on VS2 quantum dots is still at its infant stage with great potentials largely unexploited. (C) 2017 Elsevier B.V. All rights reserved.