Table 1.

Summary of currently reported SARS-CoV-2 electrochemical and electrical diagnostic platforms together with some other ones for comparison

	Target analyte	Surface ligand	Sensor characteristics	Ref.
Electrical SARS-CoV-2 sensors
GFET	S1 protein	Anti-S1 antibody	100 fg mL−1 (S1 protein) 1.6 × 101 pfu mL−1 (cultured virus) 2.42 × 102 copies mL−1	[14]
Electrochemical SARS-CoV-2 sensors
Coupled with magnetic beads	S1 protein N protein	Anti-S1 antibody on magnetic beads	6.5 pfu mL−1 (saliva)	[13]
eCovSens	S1 protein	Anti-S1 antibody	80 fM (S1 protein)	[36]
Reagent-less approach	S1 protein	Anti-S1 antibody attached to DNA bearing ferrocene	1 pg mL−1 (S1 protein) 4 × 103 viral particles mL−1	[37]
Portable platform	S1 protein	Engineered antibodies	2.2 × 102 pfu mL−1 (cultured virus) S-PCR: 72% to PCR-positive samples and 92% to PCR-negative ones	[45]
Other selected SARS-CoV-2 sensors
Abbott	N protein	Anti-N protein	S: 99.4% S-PCR: 98.3% Nasopharyngeal samples using Ct values < 33 cycles	[20]
Roche	S1 protein	Anti-S1 antibody	S: 99.68% S-PCR: 96.52%	(https://www.roche.com/media/releases/med-cor-2020-09-01b.htm)
Plasmonic sensor	SARS-CoV-2 sequence	DNA	0.22 pM	[11]
Colorimetric assay	N protein	DNA	18 ng/μL viral RNA	[24]

N protein nucleocapsid protein, S specificity, S-PCR sensitivity vs. PCR, LAMP loop-mediated isothermal amplification, GFET graphene-based field effect transistor