A sensitive immunosensor via Pd@Au0.85Pd0.15 in situ electrocatalysis generating H2O2 for quenching electrochemiluminescence of Ir(pbi)2(acac)@Ti3C2Tx MXene-PVA

Xiang Ren; Zuoxun Xie; Xiaojian Li; Dan Wu; Huan Wang; Yuyang Li; Xueying Wang; Jinxiu Zhao; Qin Wei

doi:10.1016/j.talanta.2024.126125

A sensitive immunosensor via Pd@Au_0.85Pd_0.15 in situ electrocatalysis generating H₂O₂ for quenching electrochemiluminescence of Ir(pbi)₂(acac)@Ti₃C₂T_x MXene-PVA

Talanta. 2024 Apr 24:275:126125. doi: 10.1016/j.talanta.2024.126125. Online ahead of print.

Authors

Xiang Ren¹, Zuoxun Xie¹, Xiaojian Li², Dan Wu¹, Huan Wang¹, Yuyang Li¹, Xueying Wang¹, Jinxiu Zhao³, Qin Wei⁴

Affiliations

¹ Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
² Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China; School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong, 252000, PR China. Electronic address: lixiaojian@lcu.edu.cn.
³ Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China; School of Materials Science and Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: mse_zhaojx@ujn.edu.cn.
⁴ Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China; Department of Chemistry, Sungkyunkwan University, Suwon, 16419, Republic of Korea. Electronic address: sdjndxwq@163.com.

PMID: 38663066
DOI: 10.1016/j.talanta.2024.126125

Abstract

The establishment of rapid target analysis methods for cytokeratin fragment antigen 21-1 (CYFRA 21-1) is urgently needed. [Ir(pbi)₂(acac)] (pbi = 2-(4-bromophenyl)-1-hydrogen -benzimidazole, acac = acetylacetonate) as traditional electrochemiluminescence (ECL) luminophores has been confined due to its non-negligible dark toxicity and poor water solubility leading to poor biocompatibility and electrical conductivity as an organic molecule. Hence, to overcome this limitation, [Ir(pbi)₂(acac)] can be effectively loaded on the polyvinyl alcohol hydrogel modified Ti₃C₂T_x MXene surface (Ir@Ti₃C₂T_x-PVA) as sensing platform which can emit high ECL signals. Then, a quenching strategy was proposed to fabricate an ECL sandwich immunosensor using H₂O₂ as quencher molecules which can generated by Pd@Au_0.85Pd_0.15. Especially, the generation of O₂ to H₂O₂ can be achieved through a two-electron (2e^-) reaction pathway by Pd@Au_0.85Pd_0.15, to overcome the restriction that the H₂O₂ was virtually impossible to label or immobilize on the non-enzyme nanomaterials. The proposed ECL assay achieves a response to CYFRA 21-1 within the range of 0.1 pg/mL-100 ng/mL, with a detection limit of 8.9 fg/mL (S/N = 3). This work provided a feasible tactic to seek superior-performance ECL luminophore and quencher consequently set up a novel means to makeup ultrasensitive ECL biosensor, which extended the utilization potential of Ir(pbi)₂(acac) in ECL assays.

Keywords: CYFRA 21-1; Electrochemiluminescence; H(2)O(2); Ir(pbi)(2)(acac); Ti(3)C(2)T(x) MXene.