Electrodeposition of Gold Nanoparticles on Halloysite Nanotubes Modified Glassy Carbon Electrode for Detection of Dopamine and Serotonin

Abstract

We report a novel nanocomposite composed of halloysite nanotubes (HNT) and gold nanoparticles (AuNPs) as an excellent sensing platform. Electrodeposition of AuNPs was carried out by cyclic voltammetry for 120 seconds on HNT/GCE in acidic medium to form Au/HNT/GCE. The nanocomposite was characterized by UV-visible spectroscopy and Scanning Electron Microscopy. Higher surface area was created by drop casting HNT which helped in adhering high number of AuNPs that gave rise to enhanced catalytic sites. The modified electrode was used to simultaneously detect dopamine (DA) and serotonin (SE) at nanomolar concentrations. Oxidation peaks of DA and SE was found at 0.3 V and 0.6 V adapting the differential pulse voltammetry. The limit of detection was calculated to be 9.7 × 10-6 M and 92 × 10-9 M for DA and SE respectively with S/N=3. The modified electrode exhibited high sensitivity and stability towards detection of DA and SE.