Recent Advances of Biosensors Based on Split Aptamers in Biological Analysis: A Review

Aptamers are oligonucleotides with distinct conformational shapes that allow them to bind a wide range of targets with high affinity and specificity. Compared with intact parent aptamers, split aptamers show advantages of small size and less unfavorable secondary structures, thus avoiding high background, false positive or non-specific signals well. Moreover, they are favorable to design label-free strategies since some fluorescent dyes are known to intercalate into DNA structure rather than covalent conjugation. So far, split aptamer fragments have shown good application prospects in the development of various high-performance biosensors. In this review, recent advances of biosensors based on split aptamers in biological analysis are summarized and elucidated. It includes the detection of nucleotides/nucleosides, alkaloids, proteins, antibiotics, exosomes, and tumor cells. Potential general platforms for the assay of more than one targets based on multifunctional biosensor are also included. Challenges and prospects for future development are discussed to provide valuable insights for the research of new split aptamers and aptasensors for more targets analysis.