Classifications of cobalt nanoparticles loaded into microgels (representations of components: Co nanoparticles = dark red color, cross-linked organic polymer = dark blue).

Co NPs loaded into cross-linked polymer	Abbreviation of Co NPs loaded into polymer	Structure/morphology	Pictorial diagram	References
Monometallic (Co) nanoparticles loaded into homogenous microgel	Co NPs-AAMPSA	Monometallic homogenous structure		20
Bimetallic nanoparticles loaded into homogeneous microgels	Co–Fe NPs-P(MA-AN)	Bimetallic homogenous structure		22
Inorganic nanoparticles surrounded by cross-linked polymeric organic shell loaded with Co nanoparticles	Fe3O4–SiO2@Co NPs- P(4VP)	Core = Fe3O4–SiO2		23
		Shell = Co NPs loaded P(4VP)
Cobalt nanoparticles loaded into porous microgels	Co NPs-P(4VP)	Porous hybrid microgels		26