Table 2.

Recently developed electrochemical aptasensors against different food contaminating toxins.

Toxins	Electrode details	Electrochemical transduction	The real sample analysed	Linear range	LOD	Ref.
Aflatoxin B1	GCE modified with electropolymerized neutral red and polycarboxylated thiacalix[4]arene to covalently attach by carbodiimide binding	CV and EIS	Peanut, cashew nuts, white wine and soy sauce	0.1–100 nM for EIS	0.1 nM for CV and 0.05 nM for EIS methods, respectively	s), [26]
Aflatoxin B1	TS-primer-AuNP-c-DNA was added to the stem-loop aptamer immobilised on gold electrode, underwent telomerase amplification and incubated with MB and aflatoxin. Second amplification was done by EXOIII-based catalytic degradation of ssDNA	SWV	Corn samples	0.0001–100 ppt	0.6 × 10−4 ppt	t), [26]
Aflatoxin M1	Aptamer immobilised on Fe3O4/PANi-modified Pt-microelectrodes via glutaraldehyde	CV and SWV	Milk	6–60 ng L−1	1.98 ng L−1	u), [26]
Aflatoxin M1	Amin-modified aptamer was immobilised on SPCE via diazonium bonding	EIS	Beer and wine	0.125–16 ng mL−1	0.12 ng mL−1	v), [26]
Aflatoxin B1	Gold electrode modified with Poly (amidoamine) dendrimers of fourth generation (PAMAM G4) and cystamine used to immobilize amino-modified aptamer	EIS	Peanuts-corn snacks	0.1–10 nM	0.40 ± 0.03 nM	w), [26]
Aflatoxin B1	A hexaethyleneglycol-modified the aptamer was immobilised on an SPCE through carbodiimide immobilization	EIS	Milk	2–150 ng/L	1.15 ng/L	x), [26]
Brevetoxin-2	Gold electrode modified with cysteamine and 1,4-phenylene diisocyanate. Was used to immobilise the target. The free target and fixed amount of aptamer were incubated with the electrode to establish competitive assay	EIS	Shellfish extracts	–	106 pg/mL	y), [26]
Cylindrospermopsin	GCE modified with thionine-graphene (TH-G) nanocomposite and cross-linker glutaraldehyde (GA) used to stabilise amino-modified aptamer	EIS	Water from a local lake	0.39–78 ng/mL	0.117 ng/mL	z), [26]
Endotoxin	Thiolated aptamer immobilized on gold disk electrode	EIS	–	0.01–1 ng/mL	–	[27], a)
Endotoxin	Gold electrode modified with 3-mercaptopropionic acid (MPA) was used to immobilize amine-terminated aptamer	EIS	–	0.001–1 ng/ml	1 pg/ml	[27], b)
Endotoxin	AuNPs electrodeposited on gold electrode and used to immobilize the thiolated aptamer	EIS	–	0.01–10.24 ng/ml)	0.005 ng/ml	[27], c)
Endotoxin	AuNPs modified GCE used to immobilise hairpins and incubated with 1) the released DNA1 after adding target to the Au@Fe3O4, which was attached to aptamer and its complementary sequence, DNA1; 2) nicking endonuclease; 3) with Tb–Gra nanocomposite decorated with AuNPs	DPV	–	10 fg mL−1 to 50 ng mL−1	8.7 fg mL−1	[27], d)
Endotoxin	AuNFs modified GCE immobilised HP2 () incubated with 1) the output DNA after reacting target with HP1 containing aptamer sequence 2)endonuclease 3) HP3/AuNPs/Cu-Metal organic frameworks (MOFs)	DPV	–	1.0 fg/mL to 100 ng/mL	0.33 fg/mL	[27], e)
Fumonisins B1	GCE was modified with AuNPs and aptamer-DNA duplex was immobilised on the electrode. The graphene/thionine nanocomposites was attached to the aptamer as the signal tag	CV	Wheat samples	1–106 pg/mL	1 pg/mL	[27], f)
Fumonisin B1	AuNPs electrodeposited on GCE used to stabilized thiolated aptamer	EIS	Maize samples	0.1 nM to 100 μM	2 pM	g), [27]
Microcystin-LR (MC-LR)	Aptamer was immobilized on graphene-modified SPCE	SWV	Fish extracts and tap water samples	0.1 pM to 1.0 nM	1.9 pM	h), [27]
Anatoxin-a	Disulphide modified aptamer was immobilised on Au electrode by self-assembly	EIS	Drinking water and certified samples	1–100 nM	0.5 nM	i), [27]
Saxitoxin	Au electrode modified with Octadecanethiol/MWCNTs anchored with MB used to immobilise amino-linked aptamer	DPV	Mussel samples	0.9–30 nM	0.3 nM	j), [27]
ToxinA (TOA) of Clostridium difficile	(HRP)-labeled aptamer with complementary DNA immobilized on Nafion–thionine–AuNPs-modified SPE	–	–	0–200 ng/mL	1 nM	k), [27]