An electrolyte-stable polymer composite sensor film based on 2.4% boronic acid substituted polyacrylamide (poly[acrylamide-co-3-(methacrylamido)- phenylboronic acid] or P(A-MPBA)) and polydiallyl-dimethyl-ammonium chloride (or PDDACl) is obtained in a coil-by-coil deposition procedure. Based on AFM evidence, the resulting coil aggregate deposits show ca. 5-10 nm diameter and the average film thickness increases with ca. 1 nm per deposition cycle consistent approximately with the solution coil diameter. In electrochemical experiments alizarin red S is employed as a boronic acid indicating redox probe with a Langmuirian binding constant of ca. K = 4 × 10 M and two distinct redox responses tentatively assigned here to two isomeric forms of the complex in oxidized and reduced state. Inter- and intra-coil electron transfer and electron hopping occurs during alizarin red S reduction and back-oxidation. Both smooth and mesoporous ITO substrates are employed.
Shariki, S., Cox, O. T. L., Tickell, D. A., James, T. D., Dale, S. E. C., Marken, F., Pereira Morais, M. P., Van Den Elsen, J. M. H., & Bending, S. (2012). Coil-by-coil assembly of poly[acrylamide-co-3-(methacryl-amido)- phenylboronic acid] with polydiallyldimethyl-ammonium to give alizarin red S responsive films. Journal of Materials Chemistry, 22(36), 18999-19006. https://doi.org/10.1039/c2jm31089a