Ye Zhuoxin, Liu Yibing, Pan Meichen, Tao Xiuli, Chen Yuxuan, Ma Pinyi, Zhuo Ying, Song Daqian
College of Chemistry, Jilin Province Research Center for Engineering and Technology of Spectral Analytical Instruments, Jilin University, Qianjin Street 2699, Changchun, 130012, China.
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
Biosens Bioelectron. 2023 May 15;228:115219. doi: 10.1016/j.bios.2023.115219. Epub 2023 Mar 8.
Quantum dots (QDs) have become promising electrochemiluminescence (ECL) emitters with high quantum yield and size-tunable luminescence. However, most QDs generate strong ECL emission at the cathode, developing anodic ECL-emitting QDs with excellent performance is challenging. In this work, low-toxic quaternary AgInZnS QDs synthesized by a one-step aqueous phase method were used as novel anodic ECL emitters. AgInZnS QDs exhibited strong and stable ECL emission and a low excitation potential, which could avoid the side reaction of oxygen evolution. Furthermore, AgInZnS QDs displayed high ECL efficiency (Φ) of 5.84, taking the Φ of Ru(bpy)/tripropylamine (TPrA) ECL system as 1. Compared to AgInS QDs without Zn doping and traditional anode luminescent CdTe QDs, the ECL intensity of AgInZnS QDs was 1.62 times and 3.64 times higher than that of AgInS QDs and CdTe QDs, respectively. As a proof-of-concept, we further designed an "on-off-on" ECL biosensor for detecting microRNA-141 based on a dual isothermal enzyme-free strand displacement reaction (SDR), which not only to achieve the cyclic amplification of the target and ECL signal, but also to construct a switch of the biosensor. The ECL biosensor had a wide linear range from 100 aM to 10 nM with a low detection limit of 33.3 aM. Together, the constructed ECL sensing platform is a promising tool for rapid and accurate diagnosis of clinical diseases.
量子点（QDs）已成为具有高量子产率和尺寸可调发光特性的有前景的电化学发光（ECL）发光体。然而，大多数量子点在阴极产生强烈的ECL发射，开发具有优异性能的阳极ECL发光量子点具有挑战性。在这项工作中，通过一步水相法合成的低毒四元AgInZnS量子点被用作新型阳极ECL发光体。AgInZnS量子点表现出强烈且稳定的ECL发射以及低激发电位，这可以避免析氧的副反应。此外，以Ru(bpy)/三丙胺（TPrA）ECL体系的Φ为1时，AgInZnS量子点显示出5.84的高ECL效率（Φ）。与未掺杂Zn的AgInS量子点和传统阳极发光的CdTe量子点相比，AgInZnS量子点的ECL强度分别比AgInS量子点和CdTe量子点高1.62倍和3.64倍。作为概念验证，我们基于双等温无酶链置换反应（SDR）进一步设计了一种用于检测microRNA-141的“开-关-开”ECL生物传感器，它不仅实现了目标物和ECL信号的循环放大，还构建了生物传感器的开关。该ECL生物传感器具有从100 aM到10 nM的宽线性范围，检测限低至33.3 aM。总之，构建的ECL传感平台是用于临床疾病快速准确诊断的有前景的工具。
