Fluorescent Carbon Dots Derived from Plumeria obtusa for the Detection of Metribuzin

Carbon dots (CDs) are the emerging class of carbonized materials with an ultra-small size (< 10 nm) and remarkable optical properties. In this paper, blue emissive CDs were synthesized from Plumeria obtusa (PO) flower named "PO-CDs" via a conventional hydrothermal approach. The as-prepared PO-CDs showed emission at 419 nm when excited at 335 nm with a high quantum yield (18%). This approach is effortless, inexpensive, and very reliable with the view of the green and facile method. The intensity of as-prepared PO-CDs was quenched by metribuzin pesticide via a static quenching mechanism. The reduction in PO-CDs intensity offers a wider linear range of calibration from 0.5 to 100 mu M, with the detection limit of 22.57 nM. Lastly, the interaction and quenching mechanism between PO-CDs and metribuzin confirmed by various analytical techniques. The PO-CDs-based fluorescent probe was effectively applied to detect metribuzin in the cherry tomato samples.