Table 1.

Comparison of ACE2 - based biosensors.

Type of Biosensor	Testing Sample	Assay Time (min)	LOD	Ref.
Electrochemical	saliva	6.5	229 fg mL−1	[80]
Electrochemical	saliva	4	2.8 fg mL−1	[81]
Electrochemical	saliva	60	0.35 ag mL−1	[82]
Colorimetric	NP/OP	5	0.154 pg mL−1	[83]
Colorimetricr	NP/OP	30	4.98 ng mL−1	[84]
Colorimetric	NP/OP	5	100 pfu mL−1	[85]
SERS	–	–	300 nM	[89]
SERS	urines	5	80 copies mL−1	[90]
Nano	biofluids	0.08	12.6 nM	[93]
FET	PBS	20	165 copies mL−1	[94]