Engineered aptamer for the analysis of cells

Since aptamers were discovered for about 30 years, they have already great capacity for potential applications, like biosensor construction and bioanalysis. However, for more complex analytes (e.g., cells and living organism), aptamers are unable to meet detection requirements due to excessive flexibility and high nuclease-sensitivity. In response to this dilemma, efforts have been made to develop novel engineered aptamers to expand the applications for living cell analysis, even in vivo tissues. More importantly, how to analyze cell status accurately and obtain cell information effectively via engineered aptamers has become a hot spot for researchers. Here, we review significant progress in engineering novel aptamers with various strategies and focus on engineered aptamers for different targets, including cell-targeted, protein-targeted, micromolecule-targeted and genetically encoded aptamers, to describe multiple applications in cell analysis. We further point out current problems in cell analysis and put forward future research directions.