Comparison of sample preparation procedures and LOQs with different methods^a.

Method/(ng mL−1)	Sample	Adsorbent	LOD (ng mL−1)	LOQ (ng mL−1)	Linear range (ng mL−1)	Ref.
MSPE-aptamer-ELISA	Pixian Douban	Aptamer@Fe3O4@SiO2–NH2	0.17	0.48	0.5–2	Present work
ELISA	Pixian Douban	—	0.41	1.26	0.5–2	Comparison 1
MSPE-aptamer-HPLC-MS/MS	Pixian Douban	Aptamer@Fe3O4@SiO2–NH2	0.07	0.22	0.5–10	Comparison 2
MSPE-UHPLC	Milk	PEG-MWCNTs-MNP	0.01	0.03	1.25–40	30
MSPE-HPLC	Vegetable oils	PDA@Fe3O4-MWCNTs	0.20	0.60	1–50	31
MSPD-HPLC	Crops	TBAC-hexyl alcohol DES	0.10	0.33	0.1–100	32

^aNote: “-” means the sample preparation procedures without aptamer@Fe₃O₄@SiO₂–NH₂.