Functional DNA sensors integrated with nucleic acid signal amplification strategies for non-nucleic acid targets detection

In addition to carrying and transmitting genetic material, some DNA molecules have specific binding ability or catalytic function. DNA with this special function is collectively referred to as functional DNA (fDNA), such as aptamer, DNAzyme and so on. fDNA has the advantages of simple synthetic process, low cost and low toxicity. It also has high chemical stability, recognition specificity and biocompatibility. In recent years, fDNA biosensors have been widely investigated as signal recognition elements and signal transduction elements for the detection of non-nucleic acid targets. However, the main problem of fDNA sensors is their limited sensitivity to trace targets, especially when the affinity of fDNA to the targets is low. To further improve the sensitivity, various nucleic acid signal amplification strategies (NASAS) are explored to improve the limit of detection of fDNA. In this review, we will introduce four NASAS (hybridization chain reaction, entropy-driven catalysis, rolling circle amplification, CRISPR/Cas system) and the corresponding design principles. The principle and application of these fDNA sensors integrated with signal amplification strategies for detection of non-nucleic acid targets are summarized. Finally, the main challenges and application prospects of NASAS integrated fDNA biosensing system are discussed.

Automated summary

Functional DNA (fDNA) refers to DNA molecules that have specific binding ability or catalytic function, with advantages of simple synthesis, low cost, low toxicity, high chemical stability, recognition specificity, and biocompatibility. However, the limited sensitivity of fDNA sensors to trace targets is a major challenge, especially when there is low affinity between fDNA and the targets. Various nucleic acid signal amplification strategies (NASAS) have been explored to improve the limit of detection of fDNA. This review summarizes four NASAS (hybridization chain reaction, entropy-driven catalysis, rolling circle amplification, CRISPR/Cas system) and their corresponding design principles, as well as the principle and application of fDNA sensors integrated with signal amplification strategies for the detection of non-nucleic acid targets. The main challenges and application prospects of NASAS-integrated fDNA biosensing system are also discussed.