Development of Aptamer‐Based Colorimetric Analytical Methods

This chapter discusses the progress made in the aptamer-based colorimetric assay. Aptamer generation involves three steps, which include binding, separation, and amplification. Since aptamers show a high binding affinity with their target molecules, aptamer-based sensors have been used to detect and screen for various diseases. Several aptamers are synthesized against various metal ions such as lead, mercury, and arsenic. Aptamers and gold nanoparticles (AuNPs) have proved to be suitable candidates in the biosensor, and various sensors have used these two in order to improve the detection method. Using the AuNP-based colorimetric aptasensor, researchers detected various targets and disease biomarkers with different levels of sensitivities. Among aptamer-based colorimetric assays, DNA aptamers have been involved predominantly in the development of this assay and proved with several targets. However, the limitation with this assay is that when preferring the protein as the target, it may tend to bind nonspecifically with the AuNP.