Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
J Hazard Mater. 2022 Jun 15;432:128699. doi: 10.1016/j.jhazmat.2022.128699. Epub 2022 Mar 15.
In general, suitable double luminophores and their coreactants are necessary for constructing electrochemiluminescence (ECL) ratio strategy. However, the complexity of matching double luminophores and the stability and repeatability problem suffered by introducing exogenous coreactant would greatly limit the application of ratio detection. An original single-luminophore-based ECL ratio sensing was developed excluding any exogenous coreactants in this work. The poly [9,9-bis(3'-(N,N-dimethylamino)propyl)- 2,7-fluorene]-alt-2,7-(9,9-dioctylfluorene)] nanoparticles (PFN NPs) were explored to emit two anodic ECL signals. One centered at + 1.25 V (ECL-1) with the scanning potential of 0 ~ + 1.25 V and the other at + 1.95 V (ECL-2) with the scanning potential of 0 ~ + 1.95 V. ECL-1 showed a very strong emission without any exogenous coreactant. Importantly, hydrogen peroxide (HO) was able to efficiently weaken ECL-1 but strengthen ECL-2. When organophosphorus pesticides (OPs) were absent, the immobilized acetylcholinesterase-choline oxidase (AChE-ChOx) would catalyze the substrate acetylthiocholine chloride (ATCl) to produce HO, resulting in a quenched ECL-1 and an enhanced ECL-2. With the introduction of OPs, ECL-1 increased while ECL-2 accordingly decreased as OPs prohibited production of HO by inhibiting activity of AChE. Highly sensitive ECL ratio detection for OPs was realized based on the change of the ratio of two signals. The dual anode emission properties of PFN NPs coupled with the opposite regulation of HO on the two signals paved a new avenue for potentially tunable ECL ratio sensing strategy, and showed enormous potential applications for OPs analysis.
一般来说，构建电化学发光（ECL）比率策略需要合适的双发光体及其共反应物。然而，双发光体的匹配复杂性以及引入外源性共反应物所带来的稳定性和可重复性问题，将极大地限制比率检测的应用。在这项工作中，开发了一种原始的基于单发光体的 ECL 比率传感，无需任何外源性共反应物。研究了聚[9,9-双(3'-(N,N-二甲基氨基)丙基)-2,7-芴]-交替-2,7-(9,9-二辛基芴)]纳米粒子（PFN NPs），以发出两个阳极 ECL 信号。一个信号位于+1.25 V（ECL-1），扫描电位为 0 至+1.25 V；另一个信号位于+1.95 V（ECL-2），扫描电位为 0 至+1.95 V。ECL-1 在没有任何外源性共反应物的情况下，显示出非常强的发射。重要的是，过氧化氢（HO）能够有效地减弱 ECL-1，但增强 ECL-2。当有机磷农药（OPs）不存在时，固定化乙酰胆碱酯酶-胆碱氧化酶（AChE-ChOx）将催化底物乙酰硫代胆碱氯化物（ATCl）产生 HO，导致 ECL-1 猝灭和 ECL-2 增强。随着 OPs 的引入，由于 OPs 通过抑制 AChE 的活性来阻止 HO 的产生，ECL-1 增加，而 ECL-2 相应减少。基于两个信号的比值变化，实现了对 OPs 的高灵敏度 ECL 比率检测。PFN NPs 的双阳极发射特性与 HO 对两个信号的相反调节相结合，为潜在可调谐 ECL 比率传感策略开辟了新途径，并显示出在 OPs 分析方面的巨大应用潜力。
