Review on the Selection of Aptamers and Application in Paper-Based Sensors

Abstract

An aptamer is a synthetic oligonucleotide, referring to a single-stranded deoxyribonucleic acid or ribonucleic acid ligand produced by synthesis from outside the body using systematic evolution of ligands by exponential enrichment (SELEX) technology. Owing to their special screening process and adjustable tertiary structures, aptamers can bind to multiple targets (small molecules, proteins, and even whole cells) with high specificity and affinity. Moreover, due to their simple preparation and stable modification, they have been widely used to construct biosensors for target detection. The paper-based sensor is a product with a low price, short detection time, simple operation, and other superior characteristics, and is widely used as a rapid detection method. This review mainly focuses on the screening methods of aptamers, paper-based devices, and applicable sensing strategies. Furthermore, the design of the aptamer-based lateral flow assay (LFA), which underlies the most promising devices for commercialization, is emphasized. In addition, the development prospects and potential applications of paper-based biosensors using aptamers as recognition molecules are also discussed.

Aptamers: Features, Synthesis and Applications

“…After that, it is separated using easy methods like centrifugation or magnetic separation, yielding aptamers with excellent affinity and specificity. The retention of both the spatial conformation as well as binding sites in small molecule targets is maximised by this technique [20] …”

“…The cost of aptamer screening is high. As a result, CE‐SELEX can only be used to a limited extent to screen aptamers of large molecular mass targets [20] …”

“…Free ssDNAs that do not attach to the target are absorbed by GO. Centrifugation can be used to separate ssDNA‐target complexes from non‐adsorbed free ssDNAs since this ssDNA‐target complexes are not centrifuged into the sediment [20] …”

“…micropumps, microfluidic module, microvalves, temperature control modules, reagent loading chambers, waste chamber, transfer unit, and PCR chamber are all components of the microfluidic system. This arrangement makes it possible to quickly complete several cycles of extraction and amplification [20] …”

“…Limitation of the hydrophilicity of the microchannel. It takes a lot of time to build and is not commercially available [20] …”