Establishment of the rapid electrochemical-SELEX monitoring system by using ACEF technique and its application to dengue virus aptasensor fabrication

Abstract

Aptamers, which consist of single-stranded DNA or RNA, possess considerable potential as biomolecular recognition elements. The systematic evolution of ligands by exponential enrichment (SELEX) serves as a general method for synthesizing aptamers. However, the conventional SELEX process for monitoring aptamer-target binding is time-consuming and labor-intensive, highlighting the need for rapid monitoring and selection methods. To address this problem, this study introduces a novel approach called rapid electrochemical-SELEX (RE-SELEX) monitoring method, which significantly reduces the target-aptamer binding time from 3 h to 10 min. This process is achieved by employing an alternating current electrothermal flow (ACEF) technique. The Au micro gap-type electrode was used to RE-SELEX monitoring device. As a proof-concept of this method, the dengue virus (DENV) aptamers were synthesized. For confirming the feasibility of this DENV aptamer, we analyzed target binding of produced aptamers test including gel electrophoresis, dissociation constant analysis. Then, two aptamers were selected for constructing the rapid electrochemical DENV aptasensor. The RE biosensor was achieved by ACEF technique that reduce the target-aptamer binding within 10 min. The fabricated device can detect 37 fM of the target dengue envelope protein in diluted human serum well. Thus, the proposed method provides a reliable SELEX-monitoring method for the rapid synthesis of aptamers using a simple electrochemical platform.