Selective sensing of heavy metal ions using carbon dots synthesized from Azadirachta indica seeds

Abstract

There are a notable advancement in the technology associated with using waste resources to create novel and beneficial products. It was demonstrated that the Azadirachta indica kernel component, also known as agriculture industry waste, may be used in a possibly sustainable way for the same purpose. Carbon dots (CDs) were made from agricultural waste by direct calcinations, then their surface was modified using diethylamine, sodium methoxide, and alcoholl to produce waste seed-derived luminous surface-quaternized CDs (Ai-CDs). They were used as a fluorescent nano switch to detect inorganic contaminants because of their strong photostability, excitation-dependent emission, and great water solubility, for example, ions of cadmium [Cd(II)] and arsenic [As(III)] in aqueous solutions. Ai-CDs may measure Cd+2 and As3+ concentrations by quenching luminescence ("turn-off"), and when compared to other metal ions, cupric ions selectively overpower fluorescence ("turn-on") for sensing. In present scenarios, the current method offers the benefits of quick reaction times as well as great selectivity and sensitivity. The CDs can absorb Cd2+ and As3+, which would cause a sharp dimming of fluorescence. Consequently, this unique characteristic was utilized to exclude and identify these Al3+, Cd2+, Mn2+, Ni2+, Co2+, Cu2+ and Cu+ ions, with detection limits of 5 μM to 120 μM correspondingly. Here, we demonstrate the heavy metal sensing activity of CDs from their salt solutions to project CDs as environmental friendly metal ion detecting agent. The MTT assay carried out on healthy splenocyte cells reveals that the CDs are largely non-Cytotoxicity and further it can be used for the diagonestic purposes to protect different organ diseases.