TABLE II.

Biochemical sensors for monitoring symptoms related to COVID-19.

Analyte	Type of biosensor	Type of transduction	Matrix analyzed	Limit of detection (LOD)	Reference
IFN-γ	Graphene field-effect transistor (gFET)-based aptameric sensor	FET	Sweat	7.4 × 10−13 mol l−1	90
IFN-γ, TNF-α, and IL-6	Graphene field-effect transistor (gFET)-based aptameric sensor	FET	Serum	4.76 × 10−13 mol l−1	91
			Saliva	6.08 × 10−13 mol l−1
			Urine	6.11 × 10−13 mol l−1
			Sweat
Cortisol	Molecularly imprinted polymer-based organic electrochemical transistors (OECTs)	OECTs	Sweat	Not available	95
	Antibody-electrochemical sensor	Amperometric	Sweat	2.21 × 10−10 mol l−1	96
			Saliva
	Aptamer-field-effect transistor	FET	Sweat	1 × 10−12 mol l−1	97
Na+, K+	Electrochemical-potentiometric	Sodium and potassium ISE	Interstitial fluids	Not available	98
Na+	Graphene field-effect transistor	Ion-sensitive field-effect transistor (ISFET)	Interstitial fluids	2.78 × 10−6 mol l−1	94