▎ 摘　　要

The present work reports an economic and eco-friendly strategy for fabrication of nitrogen doped fluorescent carbon nanodots (CNDs) by an electrochemical approach. Relative to previously reported approaches using harsh reaction conditions, the electrochemical approach requires less energy and reaction time for the preparation of highly stable CNDs. For the first time, four alkanolamines (ethanolamine, 3-amino-1-propanol, 4-amino-1-butanol, and 5-amino-1-pentanol) have been chosen for the preparation of CNDs, and it is found that with increase in chain length, the quantum yield (QY) value increases. The maximum QY of SI% was found for the CNDs derived from 5-amino-1-pentanol. The as-prepared CNDs have very narrow size distribution and excellent water dispersibility. The CNDs were used for quantitative detection of a nanomaterial i.e. graphene oxide without any cross-reactivity. The label-free, fluorescence sensor was also applied for the detection of graphene oxide in environmental water samples and human blood and urine samples. To explore the multifacet of as-prepared CNDs, their cytotoxicity was also studied using MCF-7 cancer cells. It was found that even at very high concentration of CNDs (2000.0 mg L-1); more than 95% MCF-7 cells are alive. Furthermore, the internalization of CNDs to the MCF-7 cells was also studied using confocal fluorescence microscopy.