Green Carbon Quantum Dots—Environmental Applications

Carbon quantum dots (CQDs) have recently gained popularity in environmental research due to their intriguing chemical and physical properties, as well as their environmental friendliness. Greener synthesised CQDs, CQDs synthesised from bio precursors using green procedures, have a better acceptability due to their more eco-friendly nature, as opposed to damaging inorganic quantum dots and CQDs made from chemical precursors. The photoluminescence (PL) or fluorescence properties of CQDs provide obvious sensing potential, and they account for the vast majority of sensing applications in CQD-based systems. CQDs have a wide range of sensing applications, as indicated by the well-known fluorescence processes in systems such as energy transfer, fluorescence quenching, and the chemical sensitivity of fluorescent spectra. The detection of pollutants in environmental systems may be regarded as the most important phase in environmental analysis, the introduction of green CQDs to this field of environmental monitoring gives value addition to this nano-carbon candidate. This chapter describes CQDs’ sensing activity toward various contaminants, including organic pollutants and heavy metal ions. It also examines the potential sensing process that underpins the usage of green CQDs in sensing applications for detecting harmful contaminants. Apart from the fluorescent sensing, chapter also dealing with the colorimetric and electrochemical sensing by CQDs, which were also came in to picture with a greater acceptance.