Intramolecular ion-channel sensors using gold electrodes immobilized with macrocyclic polyamines for voltammetric detection of adenine nucleotides

Abstract

Here, we report on two types of intramolecular ion-channel sensors using self-assembled monolayers deposited onto gold electrodes for electrochemical detection of adenosine nucleotides. In the first, macrocyclic polyaminemolecules with -SH groups were bound directly on the gold surface (covalent modification). In the second, the macrocyclic polyamine molecules with long alkyl chains were adsorbed into the mono layer of 1-dodecanethiol on the gold surface (embedment modification). These two types of electrodes have been used for the voltammetric ion-channel sensing of adenosine triphosphate (ATP 4 - ), adenosine diphosphate (ADP 3 - ), adenosine monophosphate (AMP 2 - ) and inorganic phosphate. The signals generated due to formation of supramolecular complexes between macrocyclic polyamine hosts and adenine nucleotide guests at the electrode interface were measured by cyclic voltammetry and Osteryoung square-wave voltammetry with [Ru(NH 3 ) 6 ] 3 + as an electroactive marker. The selectivity and sensitivity of the presented sensors were compared with those ion selective electrodes (ISEs) incorporated with the same and similar macrocyclic polyamines.