Sensitive determination of rutin by spectrofluorimetry using carbon dots synthesized from a non-essential amino acid.

The present study describes the synthesis of carbon dots (CDs) using a non-essential amino acid, asparagine as a precursor. The HR-TEM image shows that the size of the prepared CDs was 2.9±0.2nm with a spherical morphology. The UV-visible spectrum of CDs exhibits a major band at 307nm along with a shoulder band around 207nm corresponding to n-π* and π-π* transitions, respectively. Further, the CDs show emission maximum at 441nm when excited at 348nm. The synthesized CDs were then exploited for the determination of rutin by spectrofluorimetry based on the decrease in emission intensity at 441nm. It was found that emission intensity of CDs at 441nm was decreased while adding 0.5μM rutin to CDs. On the other hand, addition of other metal ions and anions including 5mM Mg2+ , K+ , Ca2+ , Na+ , NO3 - and oxalate, 2.5mM Cu2+ and Fe3+ and 3mM glycine, glucose, histidine, proline and cysteine does not affect the emission intensity at 441nm. A good linearity was observed for the emission intensity against 0.5-15μM rutin with a correlation coefficient of 0.997 and the limit of detection was found to be 1×10-7 M (61μg/L) (S/N=3). The real sample analysis was done by determining rutin in a pharmaceutical sample.