Bacterial Detection with Functional Nucleic Acids: Escherichia coli as a Case Study

DNA aptamers are short, single-stranded nucleic acid molecules that can bind to specific targets with high affinity and specificity. The advent of cell-SELEX technology enables the direct screening of DNA aptamers in complex cellular systems, which provides a reliable molecular recognition tool for specific cell components. In this chapter, we introduce the potential of DNA aptamers to construct a versatile molecular toolbox for cell research. We first discuss the characteristics of DNA aptamers and their advantages over antibodies, such as low cost, easy synthesis and modification, and low immunogenicity. Then, we focus on exploiting the unique properties of DNA aptamers to achieve their on-demand screening, synthesis, and modification. Furthermore, we highlight the recent advances in the DNA aptamer toolbox for cellular applications, including targeted drug delivery, imaging, biological regulation, and biomimicry. Finally, we provide some perspectives on the challenges confronted in their applications and suggest possible solutions from several aspects.