A ratiometric fluorescence and visual sensor based on conjugated polymer nanoparticles@MnO2 probe for organophosphorus pesticides detection

Qing Li; Jiangyan Zhang; Yinuo Wang; Zhiqiang He; Ziyang Xu; Minghua Zhang; Yongqiang Cheng

doi:10.1016/j.talanta.2024.127476

A ratiometric fluorescence and visual sensor based on conjugated polymer nanoparticles@MnO₂ probe for organophosphorus pesticides detection

Talanta. 2024 Dec 28:286:127476. doi: 10.1016/j.talanta.2024.127476. Online ahead of print.

Authors

Qing Li¹, Jiangyan Zhang², Yinuo Wang¹, Zhiqiang He¹, Ziyang Xu¹, Minghua Zhang³, Yongqiang Cheng⁴

Affiliations

¹ Key Laboratory of Medicinal Chemistry and Molecular Diagnosis (Hebei University), Ministry of Education, Key Laboratory of Analytical Science and Technology of Hebei Province, College of Chemistry and Materials Science, Hebei University, Baoding, 071002, Hebei, PR China.
² Key Laboratory of Medicinal Chemistry and Molecular Diagnosis (Hebei University), Ministry of Education, Key Laboratory of Analytical Science and Technology of Hebei Province, College of Chemistry and Materials Science, Hebei University, Baoding, 071002, Hebei, PR China. Electronic address: zhangjiangyan@hbu.edu.cn.
³ Department of Rehabilitation Medicine, Affiliated Hospital of Hebei University, Baoding, 071002, Hebei, PR China. Electronic address: zhangmhhbdxfy@163.com.
⁴ Key Laboratory of Medicinal Chemistry and Molecular Diagnosis (Hebei University), Ministry of Education, Key Laboratory of Analytical Science and Technology of Hebei Province, College of Chemistry and Materials Science, Hebei University, Baoding, 071002, Hebei, PR China. Electronic address: yqcheng@hbu.edu.cn.

PMID: 39742848
DOI: 10.1016/j.talanta.2024.127476

Abstract

Organophosphorus (OPs) pesticide residues pose significant threats to human health and the environment. To tackle this issue, we synthesized water-soluble fluorescent conjugated polymer nanoparticles (WSCPNs), which offer high fluorescence intensity, simple preparation methods, and ease of functionalization, making them ideal candidates for fluorescent sensing applications. These WSCPNs were subsequently used to prepare a WSCPNs@MnO₂ probe via in situ synthesis, resulting in efficient fluorescence resonance energy transfer between WSCPNs and MnO₂. This system effectively oxidizes non-fluorescent o-Phenylenediamine (OPD) into 2,3-diaminophenazine (DAP). In the absence of OPs, acetylthiocholine (ATCh) is catalyzed by acetylcholinesterase (AChE) to produce thiocholine (TCh), which reduces MnO₂ on the surface of the probe, restoring the fluorescence intensity. When OPs are present, AChE's catalytic pathway is inhibited, limiting the recovery of fluorescence intensity in WSCPNs. The remaining MnO₂ can further oxidize OPD to DAP, allowing quantitative analysis by monitoring changes in fluorescence signal ratios, achieving a detection limit of 0.0139 ng/mL. Additionally, color changes can be captured and analyzed using a smartphone, facilitating fluorescence visualization for OPs detection, achieving a detection limit of 0.025 ng/mL. This method exhibits excellent anti-interference capabilities and has been successfully applied to detect organophosphorus pesticides in leaves and soil, demonstrating the effectiveness of our ratiometric fluorescence and fluorescence visualization dual-mode sensing platform for monitoring OPs.

Keywords: Conjugated polymer nanoparticles; Fluorescence probe; Fluorescence resonance energy transfer; Fluorescence visualization; Organophosphorus pesticide; Ratiometric fluorescence.