. 2022 Nov 7;12(11):984. doi: 10.3390/bios12110984

Table 1.

Summary of ACE2-based SARS-CoV-2 biosensors.

Bioreceptor	Target	Detection Method	Immobilization/Fabrication	Support Material	Detection Limit	Shelf-Life (Room Temperature or 4–8 °C)/Portability	Time	Clinical Samples Used and Sample Size	Ref.
ACE2	S protein	EIS	ACE2 anchoring on working electrode by GA	Carbon electrode	2.18 fg mL⁻¹ S protein	7 days/portable	4 min	Yes (n = 151)	[51]
ACE2	S protein	EIS	ACE2 physiosorption on PFDT-functionalized working electrode	Gold surface	1.68 ng fg mL S protein	Shelf-life not reported/portable	30 min	Yes (n = 2)	[65]
ACE2	S protein	SWV	ACE2 immobilization on working electrode by EDC-NHS	Graphite electrode functionalized with AuNPs-cys	229 fg mL⁻¹ S protein	5 days/portable	6.5 min	Yes (n = 113)	[52]
ACE2	S protein	Chronoamperometry	A sandwich ELISA-type immunoassay	Gold electrode	22.5 ng mL⁻¹	Shelf-life not reported/portable	91.5 min	Yes (n = 4)	[113]
ACE2	S protein	Colorimetric	ACE2 immobilization by EDC/NHS	Cotton swab and gold nanoparticles	0.154 pg mL⁻¹	7 days/portable	5 min	Yes (n = 100)	[67]
ACE2	S protein	SER	ACE2 adsorption on amide-modified gold nanoarray	Gold nanoarrays on silicon substrate	80 copies mL⁻¹	Shelf-life not reported/portable	5 min	Yes (sample size not mentioned)	[54]
ACE2	S protein	LFA	ACE2 adsorbed on nitrocellulose membrane	Nitrocellulose membrane	1.86 × 10⁵ copies mL⁻¹ in clinical samples	Shelf-life not reported/portable	20 min	Yes (n = 4)	[53]