Improvement and characterization of surfactant-modified Prussian blue screen-printed carbon electrodes for selective H2O2 detection at low applied potentials

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2012-06, Vol.674, p.48-56
• Main Authors: Salazar, P., Martín, M., O’Neill, R.D., Roche, R., González-Mora, J.L.
• Format: Article
• Language: English
• Subjects: Benzethonium chloride (BZTC); carbon; detection limit; diffusivity; electrochemistry; H2O2 sensor; hydrogen peroxide; ions; permeability; potassium; Prussian blue; Screen-printed carbon electrodes (SPCEs); sodium; specific ion electrodes; Surfactant; surfactants; temperature
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2012.04.005

► Surfactant-modified electrodes displayed a higher surface concentration. ► The permeability and stability are improved in the surfactant-modified PB film. ► H2O2 sensitivity represents the highest values ever reported for SPCEs. ► Our sensors were more stable in media containing Na+ ions, even at neutral pH. ► This methodology provided a time-efficient method for producing stable PB films. The development of a highly selective and sensitive H2O2 sensor, based on the electro-deposition of Prussian blue (PB) onto screen-printed carbon electrodes (SPCEs) modified by benzethonium chloride (BZTC), is described. This methodology provides a time-efficient method for producing stable films in the presence of a BZTC concentration which was optimized with respect to electrochemical and electroanalytical properties. Some parameters such as the amount of PB deposited, film thickness, reversibility, permeability, stability, electrocatalytic properties and sensitivity to H2O2 were considered in order to select the optimal sensor. Under optimal conditions (2mM BZTC), the surface coverage and apparent diffusion coefficient for K+ displayed values of 6.4±0.2×10−8molcm−2 and 5.2×10−11cm2s−1, respectively, one order of magnitude higher than without surfactant. The catalytic rate constant for the optimized film was 2.8×103M−1s−1 which was in good agreement with data found in the literature. BZTC(2mM)/PB operating at ∼0V vs. SCE displayed the highest H2O2 sensitivity (1.07±0.03AM−1cm−2, n=5) reported in the literature to date for PB-modified SPCEs, and showed an excellent limit of detection (