Table 2. Comparison of the Immunocontrolling GO Catalytic Reaction: Spectral Methods for HCG.

system	methods	detection range ng/mL	regress equation	coefficient	LOD ng/mL
H2O2–HAuCl4	SERS	0.2–13.3	ΔI1617 cm-1 = 101.6C + 31.8	0.9905	0.07
H2O2–HAuCl4	RRS	0.5–18	ΔI = 83.7C + 108	0.9847	0.20
H2O2–HAuCl4	Abs	1.0–18	ΔA = 0.0308C + 0.036	0.9619	0.50
TCA–HAuCl4	SERS	0.67–20.0	ΔI1615 cm-1 = 43.1C – 50.8	0.9972	0.22
GS–HAuCl4	SERS	0.67–26.67	ΔI1618 cm-1 = 55.2C + 36.4	0.995	0.25