A hydrogen peroxide sensor based on the nanocomposites of poly(brilliant cresyl blue) and single walled-carbon nanotubes

Abstract

A poly(brilliant cresyl blue) (PBCB) functionalized single walled-carbon nanotube (SWCNT) modified glassy carbon electrode (PBCB/SWCNT/GCE) is fabricated by electropolymerization. The electrocatalytic activity of the PBCB/SWCNT/GCE towards the reduction of hydrogen peroxide is then investigated. The electrode shows high sensitivity [4.1 nA (μM) ⁻¹] to the electrocatalytic reduction of H₂O₂ at an applied potential of −0.30 V (vs. SCE). Important practical advantages such as a fast response time (within 5 s), a low detection limit (0.12 μM), wide linear dynamic range (4.9 × 10⁻⁷ to 2.3 × 10⁻⁴ M, R² = 0.994) and stability (remains ∼93% of its original activity after 30 days) are achieved with the PBCB/SWCNT/GCE. Further, the presence of probable interferences such as glucose, ascorbic acid, dopamine and uric acid does not interfere during the detection of H₂O₂. The application of the sensor to determine H₂O₂ in tap water with recovery values of 96% to 102% shows the sensor is suitable for routine analysis.