A comprehensive review on the capability of graphene quantum dots-based/involved platforms for the detection of inorganic ions

Substantial contamination in the ecosystem (particularly, in waterbodies) due to the disposal of hazardous substances from superfluous industrial byproducts and other human activities is one of the most serious environmental issues. Although water is among the five basic elements required for all the living beings, it is continuously becoming unsafe and unhygienic for the purpose of drinking and household activities. The presence of heavy metal ions and many toxic anions (beyond their permissible concentration) significantly contributes to water pollution. Therefore, it is judicious to detect inorganic ions in order to avoid adverse situations related to the human health and ecological imbalance. Owing to the easy affordability and unique properties of zero-dimensional graphene quantum dots (GQDs), particularly, high/tunable fluorescence, electronic conductivity, electrocatalytic activity, chemiluminescence (CL) and electrochemiluminescence (ECL), GQDs-based/involved platforms are potentially deployed for the detection of inorganic ions with reasonable selectivity and sensitivity. The versatility of these sensing probes includes the possibility of detection through fluorimetric, colorimetric, electrochemical, CL, and ECL techniques. This review aims to comprehensively inspect the deployment of GQDs-based/involved sensors for the recognition of inorganic ions, highlighting different sensing approaches with the development of performance metrics and providing insights into their underlying mechanisms. Furthermore, this collective outlook on GQDs-based/involved sensors for inorganic ions may help to identify shortcomings in the existing knowledge and influence/inspire new research with better prospects.