Plasmonic colorimetric immunosensor based on Poly-HRP and AuNS etching for tri-modal readout of small molecule

Wenying Lu; Ye Tian; Weipeng Teng; Xuchun Qiu; Ming Li

doi:10.1016/j.talanta.2023.124883

Plasmonic colorimetric immunosensor based on Poly-HRP and AuNS etching for tri-modal readout of small molecule

Talanta. 2023 Dec 1:265:124883. doi: 10.1016/j.talanta.2023.124883. Epub 2023 Jun 27.

Authors

Wenying Lu¹, Ye Tian¹, Weipeng Teng¹, Xuchun Qiu¹, Ming Li²

Affiliations

¹ Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
² Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, PR China. Electronic address: liming@ujs.edu.cn.

PMID: 37393715
DOI: 10.1016/j.talanta.2023.124883

Abstract

It was urgent to improve the intuitive, portable, sensitive and multi-modal detection method for small molecules. In this study, a tri-modal readout of plasmonic colorimetric immunosensor (PCIS) for small molecule (zearalenone, ZEN, as an example) had been established based on the Poly-HRP amplification and gold nanostars (AuNS) etching. The immobilized Poly-HRP from the competitive immunoassay was used to catalyze iodide (I^-) into iodine (I₂), which could prevent the AuNS etching by I^-. With the increasing of ZEN, the AuNS etching was enhanced, and the localized surface plasmon resonance (LSPR) peak of AuNS showed stronger blue shift, which resulted in the color changing from deep blue (no-etching) to blue violet (half-etching) and finally to shiny red (all-etching). The results of PCIS could be selectively obtained by the tri-modal readout: (1) naked eye (LOD of 0.10 ng/mL), (2) smartphone (LOD of 0.07 ng/mL) and (3) UV-spectrum (LOD of 0.04 ng/mL). The proposed PCIS had performed well in the sensitivity, specificity, accuracy and reliability. In addition, the harmless reagents were used in the overall process to further guarantee the environmental friendliness. Therefore, the PCIS might provide a novel and green avenue for the tri-modal readout of ZEN via the intuitive naked eye, portable smartphone and accurate UV-spectrum, which hold great potential for small molecule monitoring.

Keywords: AuNS etching; Plasmonic colorimetric immunosensor; Poly-HRP; Small molecule; Tri-modal readout.