Table 3. Examples of Electrochemical Biosensor Devices Developed to Early Detect Cancer Cells.

sensor	sample	analyte	electrochemical method	limit of detection	linear range	reference
dhDNA (Fc-AP-21/MB-HCP) onto GCE	human plasma	miRNA-141	SWV	0.89 fM	2.0 to 105 fM	(201)
		miRNA-21		1.24 fM
GO–CS/PVP-AuNUs onto GCE	human plasma	miRNA-141	SWV	0.94 fM	2.0 to 5.0 × 105 fM	(202)
AuNPs/Ni-catecholates/carbon black/polarized pencil graphite electrode (AuNPs/Ni-CAT/CB/PPGE)	serum samples like liquid biopsy	ctDNA from EGFR 19 Dels for NSCLC	DPV	0.32 fM	1.10–15 to 1.10–6 M	(203)
PER-CRISPR/Cas14a	synthetic samples	ctDNA EGFR L858R	DPV	0.34 fM	1 fM to 1 μM	(204)
alDNA sensor	human serum sample	KRAS point mutation level from M-DNA	SWV		100 pM to 10 nM	(187)
g-G-AuNP-dsDNA	synthetic sample	anti-p53 antibody	CV and EIS	0.6 fM	0.1 ng/L to 0.1 μg/L	(185)
SnO2-QD-Au modified with DNA onto AuE	synthetic sample	anti-p53 antibody	EIS	3.2 aM	1.10–6 to 1.10–20 M	(205)