A Novel Eplerenone Ecofriendly Fluorescent Nanosensor Based on Nitrogen and Sulfur-Carbon Quantum Dots

In this work, a novel ecofriendly optical nanosensor for detection of Eplerenone (EPL) in biological samples was reported. Highly luminescent water-soluble nitrogen and sulfur doped carbon quantum dots (N, S-CQDs) have been prepared successfully. The synthesis was based on the reaction of thiosemicarbazide (TS) as source of N and S and citric acid (CA) as source of carbon in one-step aqueous base reflux treatment. The produced N, S-CQDs have a small particle size in the range of 4.7 nm with a high quantum yield (58.5%) and high emission intensity at 446 nm under excitation wavelength of 370 nm. The unique properties of N, S-CQDs make them useful tool as a nano fluorescent probe for sensitive determination of EPL. EPL has been found to decrease the fluorescence of S, N-CDs significantly through static quenching according to the Stern - Volmer plot. The decreased intensity of S, N-CDs fluorescence was proportional to EPL in the 0.2-3.0 μM range. The limit of detection and quantitation were 0.05 and 0.15 μM, respectively. The assay of EPL by this approach was successfully done in drug formulations and in spiked human serum samples.