Table I.

Selected nanomaterial-based platforms for rapid diagnostics in COVID-19.

Disease condition	Analyte to be detected	Nanosensor material	Principle of detection	Required sample	Detection time	Limit of detection	Working range	Sensitivity/specificity
COVID-19	RdRp, spike protein	AuNTs[29]	Electrochemical	Nasopharyngeal swab	Unknown	22.2 fM	Not specified	Not specified
COVID-19	RdRp gene	g-FET[30]	Transfer curve shift	Throat swab/serum	$\sim 1$ h	2.29 fM (throat), 3.99 fM (serum)	10 fM–10 pM	$>0.97$/1.00
COVID-19	S protein	Peptide on SPAuE[31]	EIS	Nasopharyngeal swab	$\sim 15$ min	18.2 ng/ml, 0.01 copies/ml	0.05–1.0 μg/ml, ${10}^2$–${10}^3$ copies/ml	Not specified
COVID-19	SARS-CoV-2 RNA	g-FET[32]	Transistor response (I/V changes)	Nasopharyngeal swab	1–4 min	0.025-0.05 copy/μl	Not specified	0.93/1.00
COVID-19	SARS-CoV-2 Orf1ab, N genes	AIEgen@GO[33]	Fluorescence enhancement	Not specified	$\sim 1$ h	200/100 pM for Orf1ab/N cDNA	Not specified	Not reported
COVID-19	SARS-CoV-2 RNA	rGO[34]	Fluorescence	Pharyngeal swab	$\sim 35$ min	0.684 pM	1 pM–25 nM	Not reported
COVID-19	N, S protein	CNT[26]	nIR Fluorescence	Saliva	$\sim 5$ min	48 fM of N, 350 pM of S protein	0.1–100 nM	Not reported
COVID-19	Spike protein RBD	CNT[25]	Fluorescence	Not specified	$\sim 90$ min	12.6 nM of spike RBD	1 nM–1 μM	Not reported
COVID-19	RdRp gene	CNT-FET[27]	Current response	Not specified	$\sim 10$–30 min	10 fM	10 pM–1 nM	Not reported
COVID-19	N-gene	g-ssDNA-AuNP[35]	Voltage change	Nasopharyngeal swab	$<5$ min	6.9 copies/μl of viral RNA	585.4-$5.854\times {10}^7$ copies/μl	$100\%$/$100\%$
COVID-19	Viral oligonucleotides	AuNIs[36]	LSPR, plasmonic photothermal heating	Not specified	$\sim 30$ min	$0.22\pm 0.08$ pM	0.1 pM–1 μM	Not specified
COVID-19	IgM and IgG antibodies	Au[37]	Colorimeteric	Whole blood, serum or plasma	$\sim 15$ min	Not reported	Not known	$88.66\%$/$90.63\%$

SARS-CoV-2 severe acute respiratory syndrome coronavirus-2, RdRp RNA-dependent RNA polymerase, RBD receptor binding domain, CNT carbon nanotubes, nIR near infrared, GO graphene oxide, rGO reduced graphene oxide, SPAuE screen-printed gold electrode, AuNTs gold nanotriangles, AuNIs gold nanoislands, LSPR localized surface plasmon resonance.