Protocol for green synthesis of excellent fluorescent mango leaves-derived carbon for advanced theragnostic in biological applications

Carbon quantum dots (CQDs) are zero-dimensional fluorescence nanoparticles that are less than 10 nm in size. They have unique properties like tunable surface functionality, biocompatibility, fluorescence, and low toxicity. This study outlines a detailed protocol for synthesizing CQDs from mango leaf powder using a reflux method at 160 C and 400 rpm for a duration of two hours. The synthesized CQDs were comprehensively characterized using the following techniques, including UV-visible spectroscopy, fluorescent spectrophotometry, atomic force microscopy, dynamic light scattering and zeta potential measurement, Fourier transform infrared spectroscopy, and scanning electron microscopy. In vitro analysis was conducted through an MTT assay, revealing that the CQDs exhibit reduced toxicity in RPE1 cells compared to the control group. Additionally, a concentration-dependent cellular uptake assay was performed to further evaluate the biological performance of the CQDs. The findings suggest the potential of CQDs as safe and effective nanomaterials for various biological applications, including drug delivery and bioimaging.