Liu Xiaohong, Li Libo, Luo Lijun, Bi Xiaoya, Zhao Wanlin, Yan Hui, Li Xia, You Tianyan
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
Biosens Bioelectron. 2021 Jul 15;184:113232. doi: 10.1016/j.bios.2021.113232. Epub 2021 Apr 8.
Here, we show that nitrogen-doped carbon quantum dots (NCQDs) strongly inhibits the anodic electrochemiluminescence (ECL) signal of a tris(4,4'-dicarboxylic acid-2,2'-bipyridyl) ruthenium(II) (Ru(dcbpy))/tripropylamine (TPA) aqueous system. To determine the ECL-quenching mechanism, we used photoluminescence spectroscopy, UV-Visible absorption spectroscopy and dynamic simulation technology. Quenching of the ECL signal of Ru(dcbpy)/TPA by NCQDs was predominantly attributed to the interaction between Ru(dcbpy) and NCQDs rather than that between TPA and NCQDs. Specifically, when Ru(dcbpy) and NCQDs were in aqueous solution together, the carboxyl (-COOH) groups of Ru(dcbpy) were in contact with oxygen- and nitrogen-containing groups on the surface of NCQDs and formed intermolecular hydrogen bonds. This process involved energy transfer from the excited-state Ru(dcbpy) to the intermolecular hydrogen bonds, thus resulting in a decrease in the Ru(dcbpy) ECL signal. On this basis, a quenching-type ECL sensor for the quantification of NCQDs was fabricated. The sensor had a wide linear range and an estimated detection limit of 0.0012 mg mL, as well as excellent stability and selectivity. Satisfactory recoveries of 97.0-99.5% were obtained using the ECL sensor to quantify NCQDs in tap water. NCQDs could potentially be used as a quenching probe of Ru(dcbpy) to construct various biosensors with widespread applications in the sensing field.
在此，我们表明氮掺杂碳量子点（NCQDs）强烈抑制了三（4,4'-二羧酸 - 2,2'-联吡啶）钌（II）（Ru(dcbpy)）/三丙胺（TPA）水体系的阳极电化学发光（ECL）信号。为了确定ECL猝灭机制，我们使用了光致发光光谱、紫外 - 可见吸收光谱和动态模拟技术。NCQDs对Ru(dcbpy)/TPA的ECL信号猝灭主要归因于Ru(dcbpy)与NCQDs之间的相互作用，而非TPA与NCQDs之间的相互作用。具体而言，当Ru(dcbpy)和NCQDs一起存在于水溶液中时，Ru(dcbpy)的羧基（-COOH）与NCQDs表面的含氧和含氮基团接触并形成分子间氢键。此过程涉及从激发态Ru(dcbpy)到分子间氢键的能量转移，从而导致Ru(dcbpy)的ECL信号降低。在此基础上，制备了一种用于定量NCQDs的猝灭型ECL传感器。该传感器具有宽线性范围，估计检测限为0.0012 mg/mL，以及出色的稳定性和选择性。使用该ECL传感器对自来水中的NCQDs进行定量时，获得了97.0 - 99.5%的满意回收率。NCQDs有可能用作Ru(dcbpy)的猝灭探针，以构建在传感领域具有广泛应用的各种生物传感器。
