Versatile sensing strategies based on emerging programmable prokaryotic Argonautes: From nucleic acid to non-nucleic acid targets

As a class of emerging programmable endonucleases, prokaryotic Argonaute (pAgo) has attracted much attention in biotechnology. In recent years, benefiting from their stability and design flexibility of guide DNA, excellent nucleic acid cleavage capabilities, high specificity, and multiple-turnover activity, pAgo has also been applied to biosensing, providing new insights into analytical chemistry. Herein, the structure and working mechanism of common pAgos were first introduced. Then, pAgo-based sensing strategies for different targets were categorized and discussed comprehensively, emphasizing their design principles. For nucleic acid detection, in addition to commonly used cleavage activity, some assays utilize the binding activity of catalytically inactive pAgo. With the introduction of biorecognition molecules and mesophilic pAgo, pAgo was tapped to detect non-nucleic acid targets, greatly broadening their application scope. Finally, the current challenges and prospects of this field were critically discussed. This review is anticipated to provide references and ideas for developing novel pAgobased sensing platforms.