Table 6.

Summary of graphene-based wearable biosensors for detection of biomarkers in saliva and tear

Wearable device	Receptor system (s)	Detection mechanism	Biomarker	Biofluid	Disease	LOD	Ref
Patch	Graphene/AMP	LC resonant	Bacteria	Saliva	Infectious disease	Single bacterium	[240]
Bioelectronic tongue	NFZ-GQDs@ GOx and NFZ-rGO@ GOx	Electrical impedance	Glucose	Artificial saliva	Diabetes	14 µM and 32 µM	[241]
Contact lens	Graphene/GOx	Electrochemical	Glucose	Tears	Diabetes	1 µM	[242]
Contact lens	Graphene/GOx/CAT	Electrochemical	Glucose	Tears	Diabetes	12.7 µM	[243]
Ultrathin film	Graphene/PMMA/PASE	Field effect	TNF-α and IFN-γ	Artificial tears	Chronic diseases	2.75 pM	[244]
Corneal electrode	Graphene/PEDOT/TYR	Electrochemical	Dopamine	Tears	Myopia	101 × 10−9 M	[245]
Contact lens	Graphene/AgNWs/IgG	Field effect	MMP-9	Tears	OSI	0.74 ng mL−1	[246]

Abbreviations: AMP, antimicrobial peptides; NFZ, nanofibers; GQDs, glucose quantum dots; GOx, Glucose oxidase; rGO, reduced graphene oxide; CAT, catalase; PMMA, polymethyl methacrylate; PASE, 1-pyrenebutanoic acid succinimidyl ester; OSI, ocular surface inflammation; MMP-9, Matrix metalloproteinase-9; PEDOT, poly (3,4-ethylenedioxythiophene); TYR, tyrosinase