Self-assembled cyclodextrins-based nanostructures on indium-tin-oxide for a detection of catecholamine neurotransmitters

Abstract

Host-guest supramolecular systems are the leading technology to mimic biological systems. The current rapid development of non-enzymatic electrochemical sensors of neurotransmitters urges a focus towards the host-guest system on electrode that enables to selectively bind these analytes with an electrochemical response. In this study, novel method to deposit β- and γ-cyclodextrin-based self-assembled nanostructures with the sub-nanometer scale size cavities on the indium-tin-oxide glass surface was developed. The surfaces were characterized using the electrochemical, vibrational spectroscopy, and atomic force microscopy methods. We have demonstrated that these nanostructures can be easily prepared and regenerated. Our performed theoretical computations demonstrated that neutral and protonated forms of the neurotransmitters can be assembled into the cavities and reduce the ionization potential of the analytes. The electrodes with these nanostructures showed the electrochemical response to dopamine and adrenaline as the catecholamine neurotransmitters. These electrodes provide the low limit of detections in nM level, display good selectivity for these catecholamines over co-existing interferential compounds in living cells. The key advantages of the presented electrochemical systems are their simple and cheap preparation, and the ability to achieve the low levels of catecholamine concentration detections.