Synthesis of phenothiazine lead chloride perovskite quantum dots for fluorescence detection of dipicolinic acid in aqueous medium.

Water-dispersible hybrid organic-inorganic perovskite quantum dots (QDs) were synthesized using phenothiazine (PTZ) as a capping agent. The PTZ capped lead chloride perovskite ((PTZ)PbCl QDs) acted as a probe for the fluorescence detection of dipicolinic acid (DPA) via a fluorescence "turn-off" mechanism. This work illustrates that (PTZ)PbCl QDs have strong affinity toward DPA, favoring to achieve a good linear range (5.0-40 μM) with a detection limit of 46.55 nM. Additionally, a portable (PTZ)PbCl QDs integrated paper-based analytical sensing device was fabricated for fluorescence readout assay of DPA, revealing its potential for assaying of DPA with simplified analytical procedure. Furthermore, the developed (PTZ)PbCl QDs integrated fluorescence spectrometric method was successfully applied to assay DPA in human serum samples. This approach serves as a promising analytical platform for detecting DPA in biofluids, offering a simple and efficient analytical sensing method for real sample analysis.