Mn-Doped ZnS Quantum dots–An Effective Nanoscale Sensor

Quantum dots (QDs), due inter alia to their colourtunable symmetry, narrow emission, broad absorption, stability, and solution processibility have received an upsurge of interest in the last decade as potential materials for diverse applications. Doped QDs, in particular, have gained significant attention as a new class of luminescent materials since dopants influence the optical behaviour of QDs. Therefore, doped ZnS QDs possess conspicuous properties like longer dopant emission lifetime and lower toxicity. The dopant emission lifetimes of transition-metal ions are longer than the energy-gap and defect-related luminescence of the host as well as the biological background fluorescence to offer immense prospect for removal of background fluorescence for sensing applications. Probes based on phosphorescence or fluorescence enhancement of QDs is crucial for the development of the detection capability. This current review highlights the optical property and various sensing strategies of Mn-doped ZnS QDs that make them exceptional probes for applications in sensing. The review not only intends to present an all-encompassing study of the well-documented usages of QDs, but is also rather addressing the current promising improvements, concepts, and excellent applications in research of doped QDs for chemo- and biosensing. Over 200 publications are overviewed and considered here in the perspective of leading applications in sensing dealing with for instance, fluorescence, phosphorescence, chemiluminescence, electrochemiluminescence and biosensing features.