Surfactant-promoted Prussian Blue-modified carbon electrodes: Enhancement of electro-deposition step, stabilization, electrochemical properties and application to lactate microbiosensors for the neurosciences

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2012-04, Vol.92, p.180-189
• Main Authors: Salazar, P., Martín, M., O’Neill, R.D., Roche, R., González-Mora, J.L.
• Format: Article
• Language: English
• Subjects: Biosensing Techniques - instrumentation; BZT; Calibration; Carbon; Carbon - chemistry; carbon fibers; cationic surfactants; cetylpyridinium chloride; cetyltrimethylammonium bromide; Chlorides; colloids; Deposition; Electrochemical analysis; electrochemistry; Electrodes; electron transfer; Electroplating - methods; Ferrocyanides - chemistry; H2O2 sensor; hydrogen peroxide; Hydrogen Peroxide - analysis; in vivo studies; Kinetics; Lactate biosensor; Lactic Acid - analysis; Lead (metal); Microscopy, Electron, Scanning; neurophysiology; Neurosciences - instrumentation; Permeability; potassium; Prussian Blue; sodium; Solutions; Surface-Active Agents - chemistry; Surfactant; Surfactants; Time Factors
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2011.11.047

[Display omitted] ► Surfactant-modified electrodes displayed a consistently higher surface concentration. ► The permeability and stability of the surfactant-modified PB film were greater than for unmodified PB. ► Hydrogen peroxide sensitivity for surfactant-modified PB films represent the highest values reported in the literature to date for SPCEs. ► A lactate biosensor based on the PB-BZT film is described, and showed good stability and selectivity. We report here for the first time a comparison of the beneficial effects of different cationic surfactants – cetyl trimethyl ammonium bromide (CTAB), benzethonium chloride (BZT) and cetylpyridinium chloride (CPC) – for the electrochemical synthesis of Prussian Blue (PB) films, using cyclic voltammetry (CV), on screen-printed carbon electrodes (SPCEs). Their electrochemical properties were investigated, paying special attention to parameters such as the amount of PB deposited, film thickness, charge transfer rate, permeability, reversibility, stability and sensitivity to hydrogen peroxide detection. All surfactant-enhanced PB-modified SPCEs displayed a significant improvement in their electrochemical properties compared with PB-modified SPCEs formed in the absence of surfactants. Surfactant-modified electrodes displayed a consistently higher PB surface concentration value of 2.1±0.4×10−8molcm−2 (mean±SD, n=3) indicating that PB deposition efficiency was improved 2–3 fold. K+ and Na+ permeability properties of the films were also studied, as were kinetic parameters, such as the surface electron transfer rate constant (ks) and the transfer coefficient (α). The hydrogen peroxide sensitivity of surfactant-modified PB films generated by 10 electro-deposition CV cycles gave values of 0.63AM−1cm−2, which is higher than those reported previously for SPCEs by other authors. Finally, the first lactate microbiosensor described in the literature based on BZT-modified PB-coated carbon fiber electrodes is presented. Its very small cross-section (∼10μm diameter) makes it particularly suitable for neuroscience studies in vivo.