ABSTRACT

An electrochemiluminescence (ECL) aptasensor was prepared to detect Pb²⁺ 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 Pb²⁺ aptamers were covalently bound to the NCQDs to form a stable GCE/NCQDs/aptamers. On addition of Pb²⁺, the chain aptamers change to a pb²⁺ G-quadruplex conformation, which lead to a large decrease in the ECL intensity. The variation of intensity and the logarithm of the Pb²⁺ concentration had a good linear relationship (R ² = 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 Pb²⁺ aptasensor did not suffer from interference and it had good stability. The NCQDs ECL aptasensor can detect Pb²⁺ quickly and accurately, and provides a fast and efficient method for detection of Pb²⁺. Compared with literatures, the Pb²⁺ aptasensor has simpler preparation process, lower cost; furthermore, it is more environmentally friendly.

摘要

制备了电化学发光（ECL）适体传感器，以掺氮碳量子点（NCQDs）作为ECL材料来检测Pb ²⁺。为了制备工作电极，将带有羧基的NCQD负载在玻璃碳电极（GCE）上，然后将Pb ²⁺适体共价结合到NCQD上，形成稳定的GCE / NCQD /适体。添加Pb ^2+后，链适体变为pb ²⁺ G-四链体构象，从而导致ECL强度大大降低。Pb ²⁺浓度的强度和对数的变化具有良好的线性关系（R ² = 0.998）。检测范围宽（50 pM至387.9 nM），检测限低（18.9 pM）。在干扰实验中，ECL Pb ²⁺适体传感器没有受到干扰，并且具有良好的稳定性。NCQDs ECL适体传感器可以快速，准确地检测Pb ²⁺，并提供了一种快速有效的检测Pb ^2+的方法。与文献相比，Pb ²⁺适体传感器的制备工艺更简单，成本更低。此外，它更环保。