Gold nanoparticle functionalized nanopipette sensors for electrochemical paraquat detection.

Yazhou Xiong, Tao Ma, Hao Zhang, Lizhu Qiu, Shuai Chang, Yingwei Yang, Feng Liang

Mikrochimica acta 2022 Jun 10

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A sensitive nanopipette sensor is established through a unique design of host-guest recognition, which could be further enhanced by the introduction of gold nanoparticles (Au NPs). Generally, the nanopipette is conjugated with caboxylatopillar[5]arenes (CP[5]) or carboxylated leaning pillar[6]arene (CLP[6]) to generate recognition sites. After the addition of pesticide molecules, they would be captured by CP[5] (or CLP[6]), resulting in a significant electronegativity change on the nanopipette's inner surface, which could be determined by the ionic current change. The CP[5]-modified nanopipette exhibited reliable selectivity for paraquat, while the CLP[6]-modified nanopipette showed an ability of detection for both paraquat and diquat. The addition of Au NPs improved the selectivity and sensitivity of the CP[5]-Au NP-modified nanopipette for paraquat sensing. After optimization by lowering the size of the Au NPs, CP[5]-Au NPs (3 nm)-modified nanopipettes achieved lower detection limits of 0.034 nM for paraquat. Furthermore, in real sample analysis, this sensor demonstrates exceptional sensitivity and selectivity. This study provides a new strategy to develop nanopipette sensors for practical small molecule detection. The gold nanoparticles enhanced quartz nanopipette sensor based on host-guest interaction was firstly established, which could achieve an excellent limit of detection of 3.4 × 10-11 mol/L for paraquat. © 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.

Citation

Yazhou Xiong, Tao Ma, Hao Zhang, Lizhu Qiu, Shuai Chang, Yingwei Yang, Feng Liang. Gold nanoparticle functionalized nanopipette sensors for electrochemical paraquat detection. Mikrochimica acta. 2022 Jun 10;189(7):251