Enhanced electrochemiluminescence behavior of C,N quantum dots embedded g-C3N4 nanosheets and its sensing application for copper (II)

Electrochemiluminescence (ECL) is a very sensitive method for trace analysis because of its background interference and high signal-to-noise ratio. In the past decade, the determination of Cu 2+ in environment has attracted considerable attention since it plays an essential role in many physiological processes. Herein, a novel ECL sensor based on C,N quantum dots embedded g-C 3 N 4 nanosheets (C,N-QDs@NSs) was constructed for the detection of Cu 2+ . The nanocomposite was rapidly obtained via the oxidation of normal g-C 3 N 4 in H 2 O 2 solution using sonochemical synthesizing method. Due to the abundant surface defects on C,N-QDs@NSs, the ECL intensity was magnified 2.5 times for using a C,N-QDs@NSs electrode in comparision to a g-C 3 N 4 modified electrode. Besides, C,N-QDs@NSs could accelerate the rate of electron transfer in ECL reaction and thus resulted in the lower cathodic peak potential. Significantly, Cu 2+ could effectively quench the ECL of C,N-QD@NSs, which endowed C,N-QD@NSs with a great advantage in the ECL detection of Cu 2+ . under optimum conditions, C,N-QDs@NSs modified electrode exhibited a linear detection range from 5 × 10 −4 to 10 µM with a detection limit of 2 × 10 −4  µM (S/N = 3) for Cu 2+ , and was finally applied to detect Cu 2+ in real samples with satisfactory results.