Amperometric Biosensor for Choline Based on Gold Screen‐Printed Electrode Modified with Electrochemically‐Deposited Silica Biocomposite

Abstract

Abstract A mediator‐free choline biosensor was developed using the electrochemically assisted sol‐gel deposition on gold screen‐printed electrodes. The addition of 12 mM of cationic surfactant CTAB in silica sol allowed enhancing the stability of the sensor. The modified electrode demonstrated catalytic activity and stable amperometric response to choline for over 3 weeks of exploitation with the sensitivity of 6 µA mM −1 and LOD of 6 µM. The interference of ascorbic acid was reduced by pretreating the analyzed solution with MnO 2 powder. The application of the sensor with the purpose of identifying choline in the baby milk demonstrated satisfactory metrological characteristics.