Hybridization chain reaction directed DNA superstructures assembly for biosensing applications

Hybridization chain reaction (HCR) is a simple isothermal enzyme-free process with the advantages of high simplicity and versatility. Generally, initiator single-stranded DNA is amplified to form long double-stranded DNA based on a chain reaction, during which recognition and hybridization events between a pair of complementary DNA sequences occur in succession. Repeating units of HCR product can be further utilized as templates for the assembly of various nanospecies, generating complicated DNA superstructures. Therefore, HCR is regarded as an attractive technique for DNA nanotechnology, biosensing, bioimaging and biomedicine. Particularly, HCR has been utilized to develop promising biosensors for the detection of various small molecules, nucleic acids, proteins and cells. In this review, we provide a comprehensive overview of HCR directed DNA superstructures assembly for biosensing applications. We hope this review will offer readers general concept of HCR and stimulate interest, new ideas, and discoveries in the fascinating field.