Carbon dots (CDs) are zero dimensional carbonaceous nanomaterials showing tremendous physicochemical and optical properties, synthesized from any organic precursors rich in carbon content. Due to their greater biocompatibility, non-toxicity, and tiny particle size up to 10 nm, CDs have numerous applications in the field of nanosensing, bio-imaging, solar energy, light-emitting devices, photocatalyis etc. The doping of CDs with any heteroatom can improve photoluminescence (PL) properties with great photo tability and enhanced sensing limits. Thus doped CDs are in great demand for many advanced applications, including sensing heavy metal ions. Herein, Nitrogen doped CDs (NCDs) are reviewed in the light of bottom-up preparative methods to compare their optical and sensing properties towards detection of specific heavy metal ions. From this study, it is revealed that NCDs can detect specific heavy metal ion with higher selectivity by fluorescence quenching or enhancing. The PL quenching of NCDs was found to be more commonly reported for the detection of wide range of metal ion concentrations. It is revealed that NCDs propose a low-cost technology to detect toxic heavy metal ions in aqueous media, without use of any sophisticated instrumentation and specific organic ligand.
Keyword
Carbon Dots, NCDs, Heavy metal ions, Photoluminescence.
