Biosensing using hairpin DNA probes

Abstract Hairpin DNA probes (HDPs) are specially designed single-stranded DNA and have excellent sensing specificity. The past decade has witnessed the fast development of HDP-based biosensors due to the tremendous applications in biology, medicine, environmental science, and engineering. Their detectable targets include nucleic acids, proteins, small molecules, and metal ions. In this review, we summarize the recent progress in HDP-based biosensors by categorizing them into molecular beacon (MB)-based sensing in homogeneous systems and other HDP-based solid-state sensors. The basic design of MBs with diverse signaling pairs is introduced first. Then, various detectable targets and the detection principles of all HDP-based biosensors are extensively discussed. Furthermore, the methods for amplifying the response signal and improving the detection performance are covered. Finally, the limitations and possible solutions about the sensors are discussed.