Table 6.

The currently reported SERS substrates for sensing microorganic and their substrates, metal particles, target substances, and performances.

Ref.	Substrate	Metal Particles	Aptamer	Target Cell and Matrix	LOD	Linear Range
[165]	Sandwich-like structure and of Au film and Au NRs	Au NRs	anti-E. coli rabbit polyclonal	E. coli, S. aureus, and S. marcescens in suspensions	-	-
[166]	Sandwich-like structure of Fe3O4@SiO2-Au nanocomposites and Au nanostars	Graphene oxide-Au nanostars	NH2-Apt1 (Apt of E. coli) and NH2-Apt2 (Apt of S. aureus)	E. coli and S. aureus in DI water and milk.	DI water: 10 cfu/mL Milk: 102 cfu/mL	DI water: 1 × 101~1 × 108 CFU/mL, R2 = 0.994, 0.972 for E. coli and S. aureus. Milk: 1 × 102~1 × 104 CFU/mL
[167]	Sandwich-like structure of chitosan gel (CS gel) modified with E. coli Apt functionalized silver nanoparticles	gold nanostar (GNS)	The E. coli Aptamer	E. coli in DI water, milk and juice	DI water: 3.46 cfu/mL	DI water: 3.2 × 101~3.2 × 107 CFU/mL, R2 = 0.99875 milk and juice: 3.5 × 101~4 × 103 CFU/mL
[168]	Au-magnetic NPs decorated with complementary DNA strand	Au@Ag NPs	complementary DNA strand (cDNA) of S. aureus Apt	S. aureus in DI water and milk	DI water: 0.25 cfu/mL	DI water: 2.8~2.8 × 106 CFU/mL, R2 = 0.9829 milk: 1 × 102~1 × 105 CFU/mL
[169]	Au NPs	Au NPs	ROX-DNA	E. coli O157:H7 in tap water, drinking water, and milk	DI water: 0.3 CFU/mL tap water, drinking water, and milk: 1 × 103 CFU/mL	DI water: 1 × 102~1 × 107 CFU/mL, R2 = 0.99 tap water, drinking water, and milk: 1 × 103~1 × 105 CFU/mL