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.
Bibliographical noteFunding Information:
Acknowledgments: Authors are grateful to funds provided by National Natural Science Foundation of China, Shanghai Science and Technology Committee, Chinese Post−Doctoral Fund Committee and Shanghai Education Development Foundation and Shanghai Municipal Education Commission.
© 2019 by the authors. Licensee MDPI, Basel, Switzerland.
- Methyl methacrylate-n-butyl acrylate
- Multi-walled carbon nanotubes
- Solid contact ion-selective electrode