Table 1.

Mechanism, characteristics, and application of different stimuli-responsive DNA hydrogel.

Type	Stimulus	Characteristic	Mechanism	Application	Reference
Nonbiological stimuli- responsive DNA hydrogels	Temperature	T-A•T structure DNA PNIPAM hydrogel	T-A•T structure and PNIPAM have temperature sensitivity	Sensors and actuators	[35]
		Liposomes grafted onto DNA as crosslinkers	Liposomes are heat sensitive	Controlled drug release	[37]
		DNA hydrogel embedding AuNP or AuNR.	Thermoplasmonic properties of AuNPs and AuNRs	Controlled drug release and sensors	[39]
	Ions/pH	Introduction of G-rich sequence into DNA hydrogel	K+, Pb2+, and acidity convert G-rich sequence into G-quadruplex	Ion detection and drug release	[[40], [41], [42], [43], [44], [45],115]
		Specific DNAzyme	DNAzyme folded into hairpin structure in the presence of Hg2+ or Zn2+	Ion detection and drug release	[46,47]
		I-motif structure	Response to acidic environment	PH detection and drug release	[[49], [50], [51], [52]]
		C-G•C+ and T-A•T structure	Response to acidic environment	PH detection and drug release	[53]
	Photon	t-azoDNA and hairpin DNA with photolytic sequence	t-azoDNA and hairpin DNA with photolytic sequence have photo-responsiveness	Drug release Information storage	[58,62]
		DNA/DTE carboxymethyl cellulose hybrid hydrogel	DTE is characterized by cyclic and reversible photoisomerization	Controlled drug release	[59]
		CD and PpIX covalently bind to C-rich single stranded DNA	PpIX is photo-responsive	Sterilization	[60]
		UCNPs and AuNPs hybrid DNA hydrogel	UCNP–Au nanoparticles respond to NIR	Tumor therapy	[64]
	Magnetism	sDNA modified by MNPs grafted onto DNA hydrogels	Magnetic responsiveness of MNPs	Clinical medicine and nano soft robots	[66,67]
		Encapsulated multienzyme magnetic DNA hydrogel	MNPs DNA hydrogel improves enzyme activity	Detection	[68]
	Mechanical stress	Isothermal toe mediated RNA/DNA heteroduplex	The Nan connector adjusts the 3D force momentum along the TCR mechanical axis, and the hydrogel helps adjust the 2D shear modulus	Efficient capture of T lymphocytes and regulated activation of TCR	[69]
Biological stimuli-responsive DNA hydrogels	Nucleic acid	DNA motor hydrogel and DNA gated hydrogel	Complementary base pairing	Cell culture and molecular transport	[[70], [71], [72]]
		DNA hydrogels as signal amplification mechanisms	Capture probes specifically recognize targets	Detection	[[73], [74], [75],116]
		Dendritic DNA hydrogel	DNA self-assembly and expanded drug loading of dendritic hydrogels	Detection and drug loading	[[76], [77], [78]]
	Toxin	Construction of POCT with aptamer DNA hydrogel or DNA hydrogel film as detection element	The aptamer specifically recognizes the target and causes the hydrogel to cleave	Detection and sensing	[[86], [87], [88], [89]]
	ATP	Dynamically programmable DNA hydrogel	Aptamer recognizes ATP cleavage network sites	Detect ATP	[91,92]
		DNA hydrogels based on SiNPs and fluorescent probes	Aptamer recognizes ATP and turns off FRET	ATP detection and imaging	[93]
	Protein	Biorthogonal “click chemistry” prepare aptamer DNA hydrogel	Aptamer recognition, and aptamer complementary chain control protein release	Specifically adsorb and capture proteins	[94]
		DNA hydrogel as signal amplification element	Aptamer specific recognition	Detection	[95,96]
	Bacteria and viruses	Production of DNA hydrogel beads by microfluidic equipment	RCA amplification recognition probe increases sensitivity	Detection	[100]
		DNA hydrogel entrapment of AMPS	AMPs are antibacterial	Antibacterial	[102]
	Small molecules	DNA hydrogel of aptamers as bridging chains	The aptamer specifically recognizes the target, causing the hydrogel to cleave and release signal molecules	Detection and sensing	[105,117,118]
Composite class-response DNA hydrogels	Zn2+ and/or pH	Multi compartment DNA hydrogel microcapsule	Hierarchical DNA structure responds to different stimuli	“Artificial pancreas"	[110]
	Enzymes and temperature	Liposome crosslinked DNA hydrogel	The recognition site of restriction enzyme is encoded in DNA	Injectable DNA hydrogel and controlled drug release	[37]
	Water or petroleum ether	DNA/dopamine grafted dextran hydrogel	Dynamic hydrogel circuit	Regulating cell adhesion and controlled drug delivery	[112]
	Light, heat, and magnetism	Photonic crystal DNA hydrogel	Photoresist controlled coloring of photonic crystals	Information carrier	[114]