CARBON DOTS AS A FLUORESCENT SENSOR FOR DOPAMINE DETECTION

Abstract

This study explores the hydrothermal synthesis of carbon dots (CDs) from green tea, along with a thorough analysis to evaluate their size and crystallinity. The average diameter of the CDs is 4.02 ± 0.76 nm. The CDs demonstrate a distinct absorbance peak at 279 nm, revealing excitation-dependent photoluminescence (PL). The rising concentration of dopamine (DA) correlates with a reduction in the PL intensity of the CDs, thereby illustrating the efficacy of quenching. The CD-based sensor exhibits exceptional sensitivity and selectivity, evidenced by a linear Stern-Volmer (S-V) response spanning from 0.0 to 79 μM, with a detection limit established at 3.71 μM. The suggested mechanism for the decrease in photoluminescence intensity involves the inner filter effect and static quenching, which arise from the formation of complexes between CDs and DA.