Work

Waste to Wealth: Sustainable Synthesis of Green Tea‐Derived Quantum Dots for Nanomolar Detection of Fe3+ Ions and Ascorbic Acid

Year: 2025

Type: article

Abstract: Highly fluorescent carbon quantum dots are synthesized from green tea leaves via microwave pyrolysis and abbreviated as G‐CQDs. This eco‐friendly method utilizes a renewable, low‐cost, and easily accessible carbon source, with water as the solvent, aligning with green and sustainable synthesis. High‐resolution transmission electron microscopy analysis reveals an average particle size of ≈2 nm. The nitrogen content in green tea leaves facilitates surface functionalization of G‐CQDs, confirmed by X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy techniques. The G‐CQDs exhibit excitation wavelength‐dependent behavior and a high photoluminescence quantum yield of ≈45%, eliminating the need for surface passivation. The G‐CQDs show excellent photostability and environmental stability when tested under varying pH, irradiation time, and ionic strength. Additionally, they demonstrate high selectivity and sensitivity for detecting Fe3+ ions with a detection limit of 2 nM through fluorescence quenching. The fluorescence is restored in the presence of ascorbic acid (AA) due to a redox reaction with Fe3+ ions, with a detection limit of 13 nM. This dual‐sensing capability makes G‐CQDs a promising nanoprobe for rapid and on‐site detection of Fe3+ ions and AA.

Source: ChemNanoMat

DOI: 10.1002/cnma.202500140

Authors: Mandeep Kaur, Pahul P. K. Sandhu, Mallika Phull, Banibrata Maity

Institution: Thapar Institute of Engineering & Technology

Language: English

Topic: Carbon and Quantum Dots Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: bronze

Funders: Indian Institute of Technology Roorkee, Thapar Institute of Engineering and Technology, Science and Engineering Research Board