Valence-Engineered Regulation of Built-In Electric Field in Hollow CuS@CeO2 Heterojunction for Photoelectrochemical Immunoassay

IF 7.3 1区化学 Q1 CHEMISTRY, ANALYTICAL

Analytical Chemistry Pub Date : 2026-10-18 DOI:10.1021/acs.analchem.6c06355

Jiao Qin,Yang Yang,Di Wu,Shuo Tian,Man Xu,Yu He,Dianping Tang

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引用次数: 0

Abstract

Abstract Work function (Φ) strongly affects interfacial charge distribution and built-in electric field (BIEF) formation, fundamentally determining the photoelectric conversion efficiency of photoelectrochemical (PEC) sensors. Exploring the inherent correlation between Φ and BIEF is therefore essential to guide the rational design of PEC sensors. In this work, a PEC sensing platform was fabricated based on hollow CuS@CeO2 heterojunctions, where BIEF intensity was precisely regulated by cerium valence-state engineering. A robust BIEF was formed in high-valence CuS@CeO2(IV), which facilitates efficient photogenerated carrier separation and yields a high initial PEC signal. Following the sandwich-type immunoassay recognition of carcinoembryonic antigen (CEA), hydrogen peroxide (H2O2) generated by enzymatic reactions was used to react with high-valence CuS@CeO2(IV). After CuS@CeO2(IV) underwent a reduction reaction with H2O2, the Ce atoms in the heterojunction were reduced to form low-valence CuS@CeO2(III). The reduction in Ce valence states was accompanied by a decrease in work function difference (ΔΦ) values, which weakened the BIEF intensity. The weakened BIEF is unfavorable for the photogenerated carrier separation, thereby inducing an obvious decline in the PEC signal. Relying on this distinct signal variation, sensitive CEA detection is successfully realized by the PEC platform, which exhibits a linear detection range of 0.02−50 ng/mL and a low detection limit of 0.53 pg/mL. This study validates the efficacy of valence engineering in BIEF regulation, offering a promising strategy for the development of advanced PEC sensors for clinical diagnostic applications.

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空心CuS@CeO2异质结内建电场的价态调控

功函数（Φ）强烈影响界面电荷分布和内置电场（BIEF）的形成，从根本上决定了光电化学（PEC）传感器的光电转换效率。因此，探索Φ与BIEF之间的内在相关性对于指导PEC传感器的合理设计至关重要。本文基于空心CuS@CeO2异质结制备了一种电化学传感平台，并通过铈价态工程技术对其光强进行了精确调节。在高价CuS@CeO2（IV）中形成了稳健的BIEF，这有利于有效的光生载流子分离并产生高初始PEC信号。在对癌胚抗原（CEA）进行三明治式免疫测定识别后，利用酶促反应生成的过氧化氢（H2O2）与高价位CuS@CeO2（IV）反应。CuS@CeO2（IV）与H2O2发生还原反应后，异质结中的Ce原子被还原形成低价的CuS@CeO2（III）。Ce价态的降低伴随着功函数差（ΔΦ）值的降低，从而减弱了BIEF强度。减弱的BIEF不利于光生载流子分离，从而导致PEC信号明显下降。依靠这种明显的信号变化，PEC平台成功实现了CEA的灵敏检测，其线性检测范围为0.02 ~ 50 ng/mL，低检出限为0.53 pg/mL。本研究验证了价态工程在BIEF调控中的有效性，为开发用于临床诊断的先进PEC传感器提供了一个有希望的策略。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Analytical Chemistry 化学-分析化学

CiteScore

12.10

自引率

12.20%

发文量

1949

审稿时长

1.4 months

期刊介绍： Analytical Chemistry, a peer-reviewed research journal, focuses on disseminating new and original knowledge across all branches of analytical chemistry. Fundamental articles may explore general principles of chemical measurement science and need not directly address existing or potential analytical methodology. They can be entirely theoretical or report experimental results. Contributions may cover various phases of analytical operations, including sampling, bioanalysis, electrochemistry, mass spectrometry, microscale and nanoscale systems, environmental analysis, separations, spectroscopy, chemical reactions and selectivity, instrumentation, imaging, surface analysis, and data processing. Papers discussing known analytical methods should present a significant, original application of the method, a notable improvement, or results on an important analyte.