Effect of protein adsorption on hyaluronic acid/curcumin/multi-walled carbon nanotube based electrochemical sensor for detection of dopamine

Resisting protein adsorption on electrode surfaces is one of pivotal challenges in the electrochemical analysis of small bioactive molecules. In this work, we constructed a novel electrochemical sensing electrode modified with hydrophilic hyaluronic acid (HA) and curcumin/multi-walled carbon nanotube (CM/MWCNTs). The modified electrodes were comprehensively characterized for dopamine detection including the sensing sensitivity, selectivity and stability. The constructed electrochemical sensor for dopamine detection exhibited remarkable resistance to protein adsorption because of the inherent hydrophilicity of HA, and synergistically, the superior electrochemical behavior of the CM/MWCNTs composite (quinone/hydroquinone redox couples enabled superior electrochemical behavior). The HA/CM/MWCNTs/GCE performed about 5.0 folds, 3.5 folds and 2.4 folds higher electrocatalytic current for dopamine than that revealed at bare GCE, MWCNTs/GCE, and CM/MWCNTs/GCE, respectively. In addition, the HA/CM/MWCNTs-based sensor demonstrated excellent sensing performance with a low detection limit of 0.009 μM (S/N = 3) within the concentration range from 50 to 200 μM. The constructed HA/CM/MWCNTs-modified glassy carbon electrodes offered a reliable platform for the real-time monitoring of dopamine with no protein absorption.