Beschreibung:
Leakage of volatile organic compound (VOC) like ethanol in industries and presence of heavy metal ions in drinking water pose a serious threat to human health. This research develops a quantum dot sensor (nitrogen-doped carbon quantum dots (n-CDs)) for multifaceted applications. Carbon quantum dots were synthesized using hydrothermal approach from Citrus medica fruit and analysed using XPS, HRTEM, Zeta-potential, PL and EDS. The study is unique which employs the Scanning Kelvin Probe microscope (SKP) technique to investigate volatile organic compound sensing by n-CDs with contact potential difference mapping for ethanol gas sensing. n-CDs were first-ever characterized by SKP to resolute work function and VOC interactions were examined. The electron transition was studied using energy level diagrams. The luminescence quenching caused by electron transfer from n-CDs to receptors was manipulated to detect Fe3+ metal ions with a detection limit of 1.2 µM, which is well below the WHO’s acceptable limit