Table 2.

Comparing the SERS enhancement of a normal substrate with a flexible substrate.

Types of Flexible SERS Platforms	Compositions	Unique Features including Flexibility	Detection Limit	Fabrication Methods	Applications	Ref.
In situ detection for SERS	Ag NPs	Floating metal film	10−11 m (4-ATP)	One-step electronic reduction	Liquid-phase detection	[75]
	Ag/Au nanowires	3D cross-point nanostructures	10−11 m (R6G)	Nanotransfer printing	Glucose detection	[76]
Actively tunable SERS	Au NPs	An open-to-closed system	-	Cast method	Bio-macromolecules’ detection	[77]
	Wrinkled graphene/Au NPs	50% tensile strain without performance degradation	10−9 m (R6G)	Graphene transfer/physical deposition	Multiple analytes’ detection	[78]
Swab-sampling approach	Au NPs	“Sticky” feature	0.24 ng cm−2 (Thiram)	Drop-dry method	Pesticide residues’ detection	[79]
	Ag NWs	High capture capability of pesticides	40.2 ng cm−2 (PQ)	Mixing and vacuum filtration	Onsite residual-pesticide detection	[80]