SERS Detection of Dopamine Using Label-Free Acridine Red as Molecular Probe in Reduced Graphene Oxide/Silver Nanotriangle Sol Substrate

Table 1 Analytical features of the three spectral methods

Method	Regress equation	Linear range (μmol/L)	Coefficient	Detection limit (μmol/L)
SERS	ΔI=1.80C + 48	2.5–500	0.995	1.2
Fluo^a(Fig. 3(e–j))	ΔF_552nm = 0.59C + 51	50–500	0.923	25
Abs (Fig. 5)	ΔA_280nm = 0.0018C−0.03	25–500	0.996	12