“…Till date there are so many methods adopted for the synthesis of carbon quantum dots including arc discharge [1], electrochemical synthesis [2,3], combustion/thermal/hydrothermal/acidic oxidation [4][5][6][7], cage-opening of fullerene [8], supported synthesis [9][10][11], microwave/ultrasonic [12,13], laser ablation [14,15] and electrochemical oxidation methods [16,17] and so on. Carbon quantum dots gained greater acceptance because of their wide application for instance in bioimaging [18,19], nanomedicine [20,21], photocatalysis [22,23], electrocatalysis [24,25], biosensing [26,27], and chemical sensing [28,29]. It was also used as Hg 2+ , Cu 2+ , Fe 3+ , Pb 2+ and Ag + sensors [30][31][32][33][34].…”