Selective Sensing of Epinephrine by Phenylboronic Acid Tethered Carbon Dot

The present work depicts development of phenylboronic acid (PBA) derived and appended carbon dots (CD1-PBAs) to detect epinephrine with high sensitivity and selectivity against structurally analogous biomolecules like norepinephrine, L-Dopa and glucose. Carbon dots were synthesized by hydrothermal method. Microscopic and spectroscopic studies ensured the suitability of CD1-PBAs for diol sensing. Catecholic-OH groups of epinephrine primarily form covalent adduct with CD1-PBAs via boronate-diol linkage that caused change in absorption intensity of CD1-PBAs. The limit of detection (LOD) for epinephrine was found to be 2.0 nM. For other analogous biomolecules, formation of boronate-diol linkage might have got retarded by the dominant participation of secondary interactions like hydrogen bonding owing to the presence of varying functional moieties. Subsequently, responsiveness in the change in absorbance intensity of CD1-PBAs was weaker compared to that for epinephrine. Hence, a selective and efficient carbon dot (CD1-PBAs) based epinephrine sensor was developed simply by utilizing boronate-diol linkage.