Quantum dots (QDs) are nanoparticles that exhibit unique properties because of the effects of quantum confinement.1 The fluorescent capabilities of the nanomaterials are dependent on the diameter of the QDs and they have been implemented in technologies from non-invasive biosensors to QD-OLED television screens. The inherent fluorescence makes QDs appealing for more than biosensors, as pollutants can be detected through photoluminescence quenching of the nanomaterials in the presence of heavy metal ions.2 The ZnS systems have already been placed on trial as a fluorescent sensor, as the particles have already been tested as an almost analytical-grade sensor in the presence of lead(II) ions.3 This study will involve the synthesis and purification of monodisperse ZnS quantum dot systems, and initial fluorescence quenching of the materials. ZnS derivatives were synthesized from a temperature range of 230-260 ℃, and manganese(II) was successfully incorporated into the ZnS system. The system with the best monodispersity was the ZnS-Mn with 5 wt% manganese(II), which also displayed a prominent secondary fluorescent emission peak. This peak was used to determine the fluorescence quenching in the presence of lead and cadmium ions in organic solvents.
References
1. Dong, W.; Shen, H.; Liu, X.; Li, M.; Li, L. CdSe/ZnS quantum dots based fluorescence quenching method for determination of paeonol. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2011, 78, 537-542.
2. Chen, Y.; Zhou, Y.; Yin, H.; Li, F.; Li, H.; Guo, R.; Han, Y.; Ai, S. Photoelectrochemical biosensor for histone acetyltransferase detection based on ZnO quantum dots inhibited photoactivity of BiOI nanoflower. Sensors Actuators B: Chem. 2020, 307, 127633.
3. Jacob, J. M.; Rajan, R.; Kurup, G. G. Biologically synthesized ZnS quantum dots as fluorescent probes for lead (II) sensing. Luminescence 2020, 35, 1328-1337.