Selective Binding and Elution of Aptamers for Pesticides Based on Sol-Gel-Coated Nanoporous Anodized Aluminum Oxide Membrane

Abstract

Sol-gel-based mesopores allow the entry of target small molecules retained in their cavity and aptamers to bind to target molecules. Herein, sol-gel-based materials are applied to screen-selective aptamers for small molecules, such as pesticides. To enhance the efficiency of aptamer screening using a sol-gel, it is necessary to increase the binding surface. In this study, we applied the sol-gel to an anodized aluminum oxide (AAO) membrane, and the morphological features were observed via electron microscopy after spin coating. The binding and elution processes were conducted and confirmed by fluorescence microscopy and polymerase chain reaction. The sol-gel coating on the AAO membrane formed a hollow nanocolumn structure. A diazinon-binding aptamer was bound to the diazinon-containing sol-gel-coated AAO membrane, and the bound aptamer was effectively retrieved from the sol-gel matrix by thermal elution. As a proof of concept, a sol-gel-coated AAO disc was mounted on the edge of a pipette tip, and the feasibility of the prepared platform for the systematic evolution of ligands by exponential enrichment (SELEX) of the aptamer binding was also confirmed. The proposed approach will be applied to an automated SELEX cycle using an automated dispenser, such as a pipetting robot, in the near future.

Efficient Screening of Pesticide Diazinon-Binding Aptamers Using The Sol-Gel Coated Nanoporous Membrane-Assisted SELEX Process and Next-Generation Sequencing

“…The wet chemical sol-gel process can trap a pesticide in its nano-sized cavity. Further, the nanoporous AAO membrane increased the binding surface to enhance the e ciency of aptamer screening, and effectively retrieved bound aptamers from the sol-gel matrix by simple thermal elution [14].…”

“…Sol-gel was coated on the nanoporous AAO membrane to entrap the target pesticide within the sol-gel matrix to prepare the SELEX platform. The overall coating process is described in our previous report [14]. Brie y, the sol-gel composition and preparation method was performed according to the manufacturer's manual with the SolB complete kit (PCL Inc., Seoul, Korea).…”

“…One of its functional groups will have to be used for immobilization, thereby further decreasing the number of possible interactions with a future aptamer [13]. We developed a new technique for binding pesticides in a sol-gel coated-anodized aluminum oxide (AAO) membrane to solve the problem of immobilization of the target pesticide in our previous study [14].…”