Disposable Multi-Walled Carbon Nanotubes-Based Plasticizer-Free Solid-Contact Pb2+-Selective Electrodes with a Sub-PPB Detection Limit †

Yueling Liu; Yingying Gao; Rui Yan; Haobo Huang; Ping Wang

doi:10.3390/s19112550

Disposable Multi-Walled Carbon Nanotubes-Based Plasticizer-Free Solid-Contact Pb²⁺-Selective Electrodes with a Sub-PPB Detection Limit †

Sensors (Basel). 2019 Jun 4;19(11):2550. doi: 10.3390/s19112550.

Authors

Yueling Liu^{1

2}, Yingying Gao³, Rui Yan⁴, Haobo Huang⁵, Ping Wang⁶

Affiliations

¹ Department of Food Quality and Safety, College of Management, Shanghai Sanda University, Shanghai 201209, China. yuelingliu@ecust.edu.cn.
² State Key Laboratory of Bioreactor Engineering, Biomedical Nanotechnology Center, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China. yuelingliu@ecust.edu.cn.
³ State Key Laboratory of Bioreactor Engineering, Biomedical Nanotechnology Center, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China. yingyinggao_7@163.com.
⁴ State Key Laboratory of Bioreactor Engineering, Biomedical Nanotechnology Center, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China. yanrui268@126.com.
⁵ State Key Laboratory of Bioreactor Engineering, Biomedical Nanotechnology Center, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China. huanghaobo@outlook.com.
⁶ State Key Laboratory of Bioreactor Engineering, Biomedical Nanotechnology Center, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China. pwang11@ecust.edu.cn.

Abstract

Potentiometric plasticizer-free solid-contact Pb²⁺-selective electrodes based on copolymer methyl methacrylate-n-butyl acrylate (MMA-BA) as membrane matrix and multi-walled carbon nanotubes (MWCNTs) as intermediate ion-to-electron transducing layer have been developed. The disposable electrodes were prepared by drop-casting the copolymer membrane onto a layer of MWCNTs, which deposited on golden disk electrodes. The obtained electrodes exhibited a sub-ppb level detection limit of 10^-10 mol·L^-1. The proposed electrodes demonstrated a Nernstian slope of 29.1 ± 0.5 mV/decade in the linear range from 2.0 × 10^-10 to 1.5 × 10^-3 mol·L^-1. No interference from gases (O₂ and CO₂) or water films was observed. The electrochemical impedance spectroscopy of the fabricated electrodes was compared to that of plasticizer-free Pb²⁺-selective electrodes without MWCNTs as intermediated layers. The plasticizer-free MWCNTs-based Pb²⁺-selective electrodes can provide a promising platform for Pb(II) detection in environmental and clinical application.

Keywords: Multi-walled carbon nanotubes; Pb(II); methyl methacrylate-n-butyl acrylate; plasticizer-free; solid contact ion-selective electrode.

Abstract

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