Yao Haifeng, Wang Xinyi, Dong Yongping, Ye Mingfu
School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan, 243002, China.
Mikrochim Acta. 2024 Mar 18;191(4):206. doi: 10.1007/s00604-024-06290-8.
The enhanced cathodic ECL of Ru(bpy) at a bimetallic element MXenes (TiVC MXene) modified electrode in neutral aqueous condition is reported. TiVC MXene significantly catalyzed the oxygen reduction reaction (ORR) as well as the electrochemical reduction of Ru(bpy) to produce reactive oxygen species and Ru(bpy). The obtained hydroxyl radical (OH∙) not only oxidized Ru(bpy) to generate Ru(bpy) and emit light through coreactant pathway, but also oxidized Ru(bpy) to Ru(bpy), which caused an annihilation ECL reaction. As a result, two pathways occurred simultaneously to generate strong cathodic ECL signal. Sulfite removes the dissolved oxygen in water and reduces the occurrence of ORR, which prohibits the generation of OH∙ to decrease the ECL signal. The decrement of ECL intensity varied linearly with the concentration of sulfite in the range 2 nM to 50 μM with a detection limit of 0.14 nM (3σ). The proposed sensor exhibited good analytical performance, and could be used in the detection of sulfite in real samples. The results revealed that the electrocatalytic behavior of TiVC MXene is the key factor for strong cathodic Ru(bpy) ECL, which provides new application in ECL sensing field.
报道了在中性水条件下，双金属元素MXenes（TiVC MXene）修饰电极上Ru(bpy)增强的阴极电化学发光。TiVC MXene显著催化氧还原反应（ORR）以及Ru(bpy)的电化学还原，以产生活性氧物种和Ru(bpy)。所获得的羟基自由基（OH∙）不仅将Ru(bpy)氧化生成Ru(bpy)并通过共反应物途径发光，还将Ru(bpy)氧化为Ru(bpy)，这导致了湮灭电化学发光反应。结果，两条途径同时发生以产生强的阴极电化学发光信号。亚硫酸盐去除水中的溶解氧并减少ORR的发生，这抑制了OH∙的产生以降低电化学发光信号。在2 nM至50 μM范围内，电化学发光强度的降低与亚硫酸盐浓度呈线性变化，检测限为0.14 nM（3σ）。所提出的传感器表现出良好的分析性能，可用于实际样品中亚硫酸盐的检测。结果表明，TiVC MXene的电催化行为是强阴极Ru(bpy)电化学发光的关键因素，这为电化学发光传感领域提供了新的应用。
