Nitrogen-doped carbon dots as green materials for sensitive and selective detection of isorhamnetin

The overuse of beneficial flavonoid isorhamnetin can harm human liver cells, necessitating the development of an accurate detection method. In this study, water-soluble nitrogen-doped carbon dots (N-CDs) with long-wavelength fluorescence were successfully synthesised. Leveraging the fluorescence quenching phenomenon of the internal filter effect (IFE) between N-CDs and isorhamnetin, a fluorescence analytical method was developed for the detection of isorhamnetin using N-CDs as a fluorescent sensor with a good limit of detection (27.3 ng/mL) and linear range (0.25–20 μg/mL). Furthermore, N-CDs based sensor was employed to determine isorhamnetin levels in food samples, revealing a recovery range of 96.3%–103.8%. The proposed sensor represents a new, rapid, inexpensive, and environmentally friendly detection method for isorhamnetin.