Nanomolar Detection Limits of Cd2+, Ag+, and K+ Using Paper-Strip Ion-Selective Electrodes

    Authors

    S. T. Mensah; Y. Gonzalez; P. Calvo-Marzal;K. Y. Chumbimuni-Torres

    Comments

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    Abbreviated Journal Title

    Anal. Chem.

    Keywords

    SOLID-CONTACT; POTENTIOMETRIC SENSORS; CARBON NANOTUBES; MEMBRANE; ELECTRODES; CONDUCTING POLYMERS; MICROELECTRODES; TRANSDUCERS; COMPOSITES; PROTEINS; GRAPHENE; Chemistry, Analytical

    Abstract

    Paper-based ion-selective electrodes (ISEs) are simple, flexible, and cost-efficient in comparison to conventional solid-contact ISEs. Yet, paper-based ISEs have poor limits of detection (in the micromolar range) relative to conventional solid-contact ISEs. Here we describe the construction and optimization of ISEs based on commercially available filter paper modified with single-walled carbon nanotubes (SWCNTs), sputtered gold, and conductive polymer poly(3-octylthiophene) to support an ion-selective membrane. The ion-selective membrane presented here is based on the copolymer methyl methacrylate-decyl methacrylate (MMA-DMA). The copolymer MMA-DMA is highly water-repellent and has a low coefficient of diffusion, which makes it particularly suitable for the creation of sensors with high performance in reaching low limits of detection. Three different configurations of the electrodes have been characterized by using contact angle surface analysis, oxygen influence, and testing for the presence of a water layer. Paper-strip ISEs for cadmium, silver, and potassium ions were developed with groundbreaking limits of detection of 1.2, 25.1, and 11.0 nM, respectively. In addition to such low limits of detection, paper-strip ISEs display high selectivity for their ion of interest and high reproducibility.

    Journal Title

    Analytical Chemistry

    Volume

    86

    Issue/Number

    15

    Publication Date

    1-1-2014

    Document Type

    Article

    Language

    English

    First Page

    7269

    Last Page

    7273

    WOS Identifier

    WOS:000340081100020

    ISSN

    0003-2700

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