A Novel Electrochemically Deposited Hybrid Film for an Electrogenerated Chemiluminescence Sensor

Abstract

A hybrid silica film was electrodeposited on a graphite electrode from a mixed sol consisting of tetraethyl orthosilicate, a chitosan-gold nanoparticles composite, and . In the electrodeposition process, a sufficiently negative potential was applied to the electrode surface to reduce oxygen to hydroxyl ions, which served as the catalyst for the hydrolysis and condensation of tetraethyl orthosilicate. The silica, composite, and were deposited on the electrode with the condensation of tetraethyl orthosilicate. The performance of the modified electrode was characterized by scanning electron microscopy, electrochemistry, and electrogenerated chemiluminescence. These results indicate that the mass transfer rate of the hybrid film modified electrode increased due to the hydrophilic channels provided by the chitosan, and the rate of the electron transfer between and electrode surface was increased by the gold nanoparticles in the hybrid film. Oxalate was chosen as the model ion for the application of the new composite film-based electrogenerated chemiluminescence sensor. The sensor provided a linear range between 1.0 × 10⁻⁸ and 1.0 × 10⁻⁴ mol · L⁻¹ with a detection limit of 3.0 × 10⁻⁹ mol · L⁻¹ (3σ). The relative standard deviation of the biosensor to 1.0 × 10⁻⁶ mol · L⁻¹ oxalate was 2.3% for eleven successive measurements.

Keywords:

• Chitosan
• Electrodeposition
• Electrogenerated chemiluminescence
• Gold nanoparticles
• Hybrid silica film

Notes

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