Synthesis of bright blue fluorescence and water-dispersible cesium lead halide perovskite quantum dots for the selective detection of pendimethalin pesticide

Perovskite quantum dots (PQDs) have garnered a lot of interest because of their exceptional optoelectronic qualities. Halide perovskites are very water-sensitive due to their ionic composition. It has been observed that encapsulating perovskite QDs with organic or inorganic materials improve their stability; nonetheless, they frequently suffer from large aggregation size, limited water solubility, and difficulty in subsequent surface functionalization. Herein, we have reported polystyrene and cetyltrimethylammonium bromide (CTAB) as a novel ligands for the surface modification of CsPbBr3 PQDs for the rapid fluorescence detection of pendimethalin pesticide in aqueous media. The as-fabricated PS-CsPbBr3@CTAB PQDs give blue fluorescence under UV light at 365 nm and exhibit good stability. When excited at 370 nm, fluorescent PS-CsPbBr3@CTAB PQDs display emission intensity at 436 nm. Upon addition of pendimethalin pesticide, the fluorescence of PS-CsPbBr3@CTAB PQDs was dramatically quenched, which yields to fluorescence turn-off. Noticeably, a linear quenching was achieved with increasing concentration of pendimethalin pesticide (5.0-100 & mu;M) with the detection limit of 30.34 nM. Moreover, the as-synthesized PS-CsPbBr3@CTAB PQDs acted as a sensor for accurate assay of pen-dimethalin in potato and apple with low relative standard deviation values.