A simple electrochemiluminesecence aptasenor using a GCE/NCQDs/aptamers for detection of Pb.

An electrochemiluminescence (ECL) aptasensor was prepared to detect Pb with nitrogen-doped carbon quantum dots (NCQDs) as ECL materials. To prepare the working electrode, NCQDs with carboxyl groups were loaded on a glassy carbon electrode (GCE) and then Pb aptamers were covalently bound to the NCQDs to form a stable GCE/NCQDs/aptamers. On addition of Pb, the chain aptamers change to a pb G-quadruplex conformation, which lead to a large decrease in the ECL intensity. The variation of intensity and the logarithm of the Pb concentration had a good linear relationship ( = 0.998). The detection range was wide (50 pM to 387.9 nM) with a low detection limit (18.9 pM). In interference experiments, the ECL Pb aptasensor did not suffer from interference and it had good stability. The NCQDs ECL aptasensor can detect Pb quickly and accurately, and provides a fast and efficient method for detection of Pb. Compared with literatures, the Pb aptasensor has simpler preparation process, lower cost; furthermore, it is more environmentally friendly.