Fluorescent detection of Pb2+ pollutant in water samples with the help of Delonix regia leaf-derived CQDs

Abstract

Heavy metals released from different sources into water bodies are a major concern in the view of environmental protection. Their non-biodegradability and the numerous health hazards add to the issue. Scientists worldwide have emphasized the issue and are trying to resolve it by different means. Among all the methods, the fluorescent method stands out for its simplicity and rapid results. Here, the study focuses on the development of an efficient and sustainable method for the detection of lead in waste-water effluents. Carbon quantum dots (GCDs), a highly non-toxic substance developed from Delonix regia leaves for the purpose via a simple hydrothermal method. The prepared GCDs exhibited good photostability and water solubility; they also displayed a bright red emission when irradiated with ultraviolet (UV) light. Here, the authors propose the synthesized GCDs as an effective fluorescent probe for sensitive detection of lead ions in aqueous samples. Photoluminescence quenching of GCDs by the addition of lead was studied and a good detection limit of 3.3 nM with a linear range of 10–180 µM was achieved. Further, real sample analysis was also conducted to prove the applicability of the synthesized GCDs.