Multifunctional Receptor with Tunable Selectivity: A Comparative Recognition Profile of Organic Nanoparticles with Carbon Dots.

The exponential growth in the research field of water pollution control demands the evolution of novel sensing materials for regulation and quantification of metals ions.  Within this context, the current work reports a new strategy for the synthesis of carbon dots from the hydrothermal treatment of organic nanoparticles. The organic nanoparticles are found to be selective towards Cs (I) ions with a detection limit of 5.3 nM, whereas the highly fluorescent carbon dots are found to be selective towards Ag (I) ions with detection limit of 4.8 nM. Both the sensing systems illustrate rapid sensing with working pH range from 4-9. The interfacial molecular restructuring of the sensing systems in aqueous phase has been investigated in the absence and presence of targeted metal ions using sum frequency generation vibrational spectroscopic tool. The practical applicability of the sensors was checked in environmental samples. This work opens new avenues for the exploration of temperature guided sensing modulation in nanomaterials.