Metal-to-particle charge transfer invoked photoelectrochemistry on ferroelectric SrTiO3 for split-mode and high-throughput aptasensing

Qi Zhang; Mengmeng Gu; Lan Zhang; Xiuming Wu; Guang-Li Wang

doi:10.1016/j.aca.2024.343318

Metal-to-particle charge transfer invoked photoelectrochemistry on ferroelectric SrTiO₃ for split-mode and high-throughput aptasensing

Anal Chim Acta. 2024 Dec 1:1331:343318. doi: 10.1016/j.aca.2024.343318. Epub 2024 Oct 9.

Authors

Qi Zhang¹, Mengmeng Gu¹, Lan Zhang¹, Xiuming Wu¹, Guang-Li Wang²

Affiliations

¹ Key Laboratory of Synthetic and Biological Colloids (Ministry of Education), School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China.
² Key Laboratory of Synthetic and Biological Colloids (Ministry of Education), School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China. Electronic address: glwang@jiangnan.edu.cn.

PMID: 39532414
DOI: 10.1016/j.aca.2024.343318

Abstract

Split-mode aptasensing is highly desirable in photoelectrochemistry because of its distinctive advantages of high-throughput, avoided damage to biomolecules, and increased sensitivity and selectivity. However, the currently available photoelectrochemical (PEC) strategy conducible to split-mode aptasensing is still limited to the bioreaction mediated generation of photoactive species, in which a low photocurrent was usually attained, rending this strategy impotent for attaining high sensitivity. As a result, to explore new strategies that are amendable to highly efficient, split-mode PEC aptasensing are still challenging but demanding. Herein, ferrocyanide mediated metal-to-particle charge transition (MPCT) on ferroelectric strontium titanate (SrTiO₃) was explored as an innovative signal transduction strategy and was validated for high-performance aptasensing. By taking the 17β-Estradiol (E2) as a model analyte, the recognition between the target (E2) and its aptamer anchored on the Fe₃O₄@Au (named as Fe₃O₄@Au/Apt) destroyed the beforehand formed assembly between the Fe₃O₄@Au/Apt and the ssDNA labeled liposome encapsulated with [Fe(CN)₆]^4- (named as DLL-FeCN), which resulted in the release of the beforehand encapsulated [Fe(CN)₆]^4- into solution. The released [Fe(CN)₆]^4- then coordinated onto the surface of SrTiO₃ nanoparticles consisted photoelectrode, forming the MPCT process from metal ion (iron (II) in [Fe(CN)₆]^4-) to the conduction band (CB) of SrTiO₃ for anodic photocurrent signal output. The detection achieved linear range of 1.0 pM-100 nM, with a detection limit of 0.3 pM for E2. Benefiting from the cooperative effects of the MPCT process and the ferroelectric polarization in bulk SrTiO₃ for achieving highly efficient photocurrent generation capability, the developed split-type detection had the advantage of high sensitivity/selectivity and high throughput. This work not only opens up the MPCT process for innovative PEC sensing strategy but also blazes a new road for high performance PEC aptasensing.

Keywords: Ferroelectric strontium titanate; High-throughput aptasensing; Metal–to–particle charge transition; Split–mode detection.