Biosensor based on laccase-halloysite nanotube and imidazolium zwitterionic surfactant for dopamine determination

Zwitterionic surfactants incorporated nanomaterials and biomolecules structures offers enhanced catalytic activities and stabilities in biosensing. Herein, we present the construction of biosensors using graphite, a class of imidazolium zwitterionic surfactants, 3-(1-alkyl-3-imidazolio)-propane-sulfonate (ImS3-n; n = 10, 12, 14, 16) and laccase (Lac) immobilized on clay halloysite nanotube (HNT) in a carbon paste electrode (CPE). The Lac-HNT-ImS3–14/CPE showed to be the most promising biosensor due to the low capacitance and fastest electronic charge transfer using the probe hexacyanoferrate. Therefore, the surfactant ImS3–14 was characterized by spectroscopic techniques such as 1H, 13C NMR and ESI-MS. The developed biosensor was used to create a novel electroanalytical method for the determination of dopamine by square-wave voltammetry (SWV). Under optimized conditions, the calibration plot showed a linear range for dopamine of 0.99–67.8 µmol L−1 using SWV. The limit of detection calculated was 0.252 µmol L−1. The biosensor was successfully applied in the determination of dopamine contained in pharmaceutical samples, and the new proposed sensor was obtained with a recovery range from 97.6% to 108.7 % (n = 3). The Lac-HNT-ImS3–14/CPE biosensor is presented here as a new laccase-based biosensor with outstanding characteristics, which offered an elegant way for interfacing the electrochemical biosensor at the molecular level. It also plays a significant role in electronic signal transduction and biological recognition processes.