High-Quality Conjugated Polymers Achieving Ultra-Trace Detection of Cr2O72- in Agricultural Products

Hui Li; Fei Li; Fang Liu; Xiao Chen; Wenyuan Xu; Liang Shen; Jingkun Xu; Rui Yang; Ge Zhang

doi:10.3390/molecules27134294

High-Quality Conjugated Polymers Achieving Ultra-Trace Detection of Cr₂O₇^2- in Agricultural Products

Molecules. 2022 Jul 4;27(13):4294. doi: 10.3390/molecules27134294.

Authors

Hui Li¹, Fei Li¹, Fang Liu¹, Xiao Chen², Wenyuan Xu², Liang Shen², Jingkun Xu^{3

4}, Rui Yang⁵, Ge Zhang²

Affiliations

¹ School of Pharmacy, Jiangxi Science and Technology Normal University, Nanchang 330013, China.
² School of Chemistry and Chemical Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013, China.
³ Jiangxi Key Lab of Flexible Electronics, Flexible Electronics Innovation Institute, Jiangxi Science and Technology Normal University, Nanchang 330013, China.
⁴ College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
⁵ School of Electronics and Information Engineering, Changshu Institute of Technology, Changshu 215500, China.

Abstract

In view of that conjugated polymers (CPs) are an attractive option for constructing high-sensitive Cr₂O₇^2- sensors but suffer from lacking a general design strategy, we first proposed a rational structure design of CPs to tailor their sensing properties while validating the structure-to-performance correlation. Short side chains decorated with N and O atoms as recognition groups were instructed into fluorene to obtain monomers Fmoc-Ala-OH and Fmoc-Thr-OH. Additionally, their polymers P(Fmoc-Ala-OH) and P(Fmoc-Thr-OH) were obtained through electrochemical polymerization. P(Fmoc-Ala-OH) and P(Fmoc-Thr-OH) with high polymerization degrees have an excellent selectivity towards Cr₂O₇^2- in comparison to other cations and anions. Additionally, their limit of detection could achieve 1.98 fM and 3.72 fM, respectively. Especially, they could realize the trace detection of Cr₂O₇^2- in agricultural products (red bean, black bean, and millet). All these results indicate that short side chains decorated with N and O atoms functionalizing polyfluorene enables the ultra-trace detection of Cr₂O₇^2-. Additionally, the design strategy will spark new ideas for the construction of highly selective and sensitive Cr₂O₇^2- sensors.

Keywords: Cr2O72−; agricultural products; conjugated polymer; design strategy; ultra-trace detection.

MeSH terms

Polymers* / chemistry

Substances

Polymers

Grants and funding

This research was funded by the National Natural Science Foundation (52073128, 51863009, 5210031010), Natural Science Foundation of Jiangxi Province (20212BAB203012), Scientific Research Foundation for Doctors in Jiangxi Science and Technology Normal University (2017BSQD006), Projects for Postgraduate Innovation in Jiangxi (YC2021-X02).