Table 1.

Summary of the different types of DNA-based biosensors.

Category		Advantages	Disadvantages	Detection Object
Functional DNA strand-based biosensors	DNA aptamer	Easily accessed; easily modified; adjustable affinity; more economic; more durable lifetime	Requires multi-round selection; easily attacked by the nucleic enzyme; potential biotoxicity	IFN-γ [64,65]
				Pb2+ [77]
				Thrombin [69,83]
	DNAzyme	High catalytic activity; small molecule detection with high sensitivity	Easily affected by temperature; needs oxidative substrate; the reaction product cannot be recycled to use	Pb2+ [102]
				AMP, Lyso [106]
				Bleomycin [107]
DNA hybridization-based biosensors	DNA hairpin	Detects nucleic acids with high selectivity; easily converts the hybridization process into physical signal change	Easily damaged by temperature	DNA [117,118,119]
	HCR	High sensitivity, especially at the biosensing interface	Easily be triggered automatically by mistake	micro-RNA [121]
	CHA	More stable than HCR	Not as sensitive as HCR	micro-RNA [122]
DNA template-based biosensors	DNA tiles	Effectively adjust the surface density of bioprobes; suitable for in vivo biosensing	Lack of the ability to form complex and large-scale patterns	mi-RNA 141 [155]
	DNA origami	Control the arrange of bioprobes and materials with nanoscale accuracy; programmable nanostructure	Time-consuming annealing process; expensive; difficult to design	Oligonucleotides [177]
				Thrombin [160,182]