Fluorescence-Based Detection of Iron Using Carbon Quantum Dots Derived from Camellia Sinensis (Tea) Extract

This study presents the green synthesis, characterisation, and application of carbon quantum dots (CQDs) derived from Camellia sinensis (tea) extract for the selective detection of Fe³⁺ ions. Employing a microwave-assisted carbonisation method in a mildly acidic medium, the synthesised CQDs exhibited bright green fluorescence under UV light. They demonstrated high sensitivity to Fe³⁺ ions via a fluorescence quenching mechanism. Quenching efficiency was found to be dependent on Fe³⁺ ion concentration, allowing quantitative analysis with minimal interference from other metal ions such as those of Mg2+, Zn2+, and Cu2+. The developed detection method is simple, cost-effective, eco-friendly, and suitable for environmental monitoring, agricultural soil analysis, and biomedical diagnostics applications. The project highlights the potential of tea-derived CQDs as a sustainable alternative to traditional, resource-intensive iron detection techniques, aligning with the principles of green chemistry and addressing practical needs in real-world scenarios.