Recent trends in use of plant-derived carbon dot-based fluorescent probes for heavy metal ion detection and their biological applications

Abstract

Plant-derived carbon dots (CDs) have drawn a lot of interest as superior nanomaterials because of their sustainable nature, biocompatibility, and environmentally friendly synthesis, which sets them apart from other CDs made from non-renewable resources. The synthesis of CDs from natural sources such as fruits, leaves, bark, stem, flower, seed and biowaste by hydrothermal, pyrolysis, and microwave-assisted method have been investigated to modify the size and features of CDs. The plant-derived CDs exhibit greater sensitivity and selectivity, and their high photoluminescent properties makes it possible to detect physiological and ecological significant metal ions like iron (Fe³⁺), copper (Cu²⁺), lead (Pb²⁺), and mercury (Hg²⁺). This study focuses mainly on crucial elements such as absorption, emission, sensitivity, selectivity, and limits of detection of metal ions, a thorough examination of their sensing characteristics is provided. This review article comprehensively summarizes plant-based CDs with different synthesis methods, characterization techniques, metal ion sensing and its mechanism, stability and biological imaging of CDs. Additionally, we discussed the plant derived CDs for the detection of pesticides and drugs. These CDs also find extensive applications in environmental remediation by offering a sustainable alternative for detecting harmful pollutants. Beyond these sensing, their biological uses of plant-derived CDs, such as bioimaging, antioxidant activity, and therapeutic potential, are finally addressed. This review emphasizes the bright future of plant-derived CDs in biomedicine and sustainable nanotechnology, with a focus on their biological applications and improved sensing capabilities in research development.