Development of Multifunctional C-dots from Processing Waste of Pomelo Fruits for Determination of pH and Methyl...

Multifunctional fluorescent C-dots from Pomelo wastes (peel/pomace) were produced using microwave and hydrothermal treatment. Surface of synthesized C-dots were modified to detect the pesticide in food samples. Synthesized C-dots and functionalized C-dots were characterized using FTIR; SEM; and UV spectroscopy. Microwave synthesized C-dots were of amorphous structure and particle size were in the range of 0.4 to 2.5 nm. The surface passivated C-dots were used as a nanoprobe for cost-effective detection of methyl parathion in food samples; however C-dots without surface passivation were utilized sucessfully for the development of pH paper for determination of pH (3.5-12.5). Fluorescent intensity of developed pH paper varied linearly with the change in the pH. Utilizing optical characteristics and a large number of surface functional groups, C-dots have a potential to be used as a fluorescence or fluorescent sensor to detect methyl parathion from food samples by following the "turn-on-off" mechanism. LOD and LOQ level of surface passivated C-dots were 0.12 and 0.46 mg/L respectively for parathion methyl pesticide.