Quinone-based fluorophore: A promising luminescent functional material for effective sensing of serine

•A sulfur-incorporated 1,4-naphthoquinone (“ligand”) has been identified as a receptive and discriminating chemical sensor for serine in semi-aqueous medium.•Fluorometric sensing of serine has been observed by unaltered routes of fluorescence quenching respectively.•Selectivity of “ligand” towards serine remained unaltered in the existence of a group of competing amino acids.•The value of detection limit found 0.22 µM (against serine). In the recent decade, the redox-active quinone entity has been exhaustively evaluated as a potential drug-like molecule. However, there are only few reports that have demonstrated its applicability as a sensor-like motif against biological analytes. In pursuit of our curiosity into the sensor-like characteristics of small molecules, this report investigates into the utility of a sulfur-containing naphthoquinone-based “ligand” as a selective and sensitive fluorimetric sensor for the amino acid such as serine, in semi-aqueous medium by distinct mechanisms of fluorescence quenching respectively. The stoichiometry of coordination of “ligand” with serine was evaluated from B-H plot and found to be 1:1, along with a significantly low detection limit of 0.28 µM (Stern-Volmer plot), respectively. The efficacy has also been verified in presence of a select array of competing amino acids, in real water samples. [Display omitted]