Table 1.

Summary of representative carbon-based nanomaterials used in electrode and label of electrochemical biosensor

Materials	Advantage	Limitations	Feature	Limit of detection	Ref.
SWCNT	Large surface area to volume ratio (S/V) Low charge-carried density Delocalized π-orbitals Electrical conductivity improvements	Limited surface to interface with large biological components Nonspecific adsorption of protein Difficult manipulation during sensor fabrication process Difficult chemical functionalization	Electrode	DeoxyriboNucleic acid (DNA) 71 pM	[13]
			Electrode	Glucose 7.06 μA/mM	[14]
			Electrode	aflatoxin B1 (AFB1) 0.01 nM	[15]
			Electrode	Anti-IgG 0.2 pM	[16]
MWCNT	Excellent conducting and electro-catalytic properties	Need to functionalize surface for increasing biocompatibility Irreversible agglomerates in aqueous solution	Electrode	Carcinoembryonic antigen (CEA) 0.0055 fM	[17]
			Electrode	Transforming growth factor beta 1 (TGF-β1) 0.05 pM	[9]
			Electrode	Prostate specific antigen (PSA) 0.11 fM	[18]
			Electrode	Mouse IgG 0.066 pM	[19]
			Label	PSA 0.13 pM	[20]
Graphene	High S/V Large active sites Fast electron transfer High thermal conductivity Better mechanical flexibility Good biocompatibility	Hard to dissolve in water	Electrode	dibutyl phthalate (DBP) 0.025 μM	[21]
			Electrode	PSA 0.33 pM	[22]
			Electrode	Cystatin C 0.002 nM	[23]
			Label	Cry1C 0.02 pM	[24]
			Label	CEA 0.003 pM	[25]