Kitchen Waste-Derived Oxygen-Doped Fluorescent Carbon Quantum Dots for Ultra-Trace Detection of Chromium(VI) in Environmental Water Matrices

Developing a green sensor using agro-industrial and kitchen wastes is a novel approach to maintain sustainability and overcome the cost of the available chemical-based sensors.Hexavalent chromium determination is crucial for public health due to widespread sources and high toxicity, yet challenges remain in detection due to interference from nontarget ions and complex matrices.In this report, we synthesized garlic peel-derived waterdispersed blue-emitting carbon quantum dots, having an approximate diameter of 4 nm and functionalized with carbonyl, hydroxyl, and carboxylic acid groups.The prepared materials are useful for selective and sensitive detection of the most toxic hexavalent chromium ions in real water samples.The sensing method was validated linearly over a concentration range of 7-100 M, with the limit of detection and the limit of quantification values of 95.14 and 317.92 ppb, respectively.This fluorescence sensing platform demonstrated a strong anti-interference capability under real and controlled laboratory experimental conditions.The effectiveness of the proposed fluorescence-quenching-based technique was also confirmed by benchmarking its results with inductively coupled plasma optical emission spectroscopy.The proposed sensor's efficiency with environmental samples highlights it as a promising candidate for future market implementation.