Multiplexed electrochemical aptasensor on a nanoporous electrode: towards sensitive and anti-fouling detection of procaine, ATP and adenosine in biofluids.

This study presents a green and simple one-step electrochemical strategy for preparing nanoporous gold electrodes. The method involves anodizing the gold electrode by linear sweep voltammetry (LSV) in an aqueous solution of l-ascorbic acid (AA) and hydrochloric acid (HCl). The gold electrodes were etched in solution by hydrochloric acid to generate complexes, which were simultaneously reduced to gold nanoparticles due to the presence of ascorbic acid, resulting in the formation of a porous structure on the electrode surface. Compared with the smooth electrode, the nanoporous gold electrode prepared by this method has a considerable larger electroactive area. The prepared electrode was used to construct an electrochemical aptamer-based (EAB) sensor, which demonstrated high sensitivity and good antifouling performance in the rapid detection of small molecules including procaine, adenosine triphosphate (ATP) and adenosine (ADE). This study provides a new and efficient way for the preparation of nanoporous gold electrodes, which is expected to be more widely used and further developed in biosensing and clinical point-of-care testing.