Table 1.
An overview of recent electrochemical biosensors for toxins determination.
| Electrode | (Bio)Sensor Format | Electrochemical Technique | Analyte/Sample | L.R. | LOD | References |
|---|---|---|---|---|---|---|
| SPCEs | Label-free electrochemical aptasensor based on DNA nanotetrahedron and DNA triplex | SWV | Saxitoxin/seawater | 1–400 nM | 0.92 nM | [43] |
| CB-SPCEs | Enzyme-linked immunomagnetic electrochemical (ELIME) assay | CA | DA/shellfish scallop | 5–62 ng mL−1 | 0.4 ng mL−1 | [53] |
| Phosphorene–gold–SPCE (BP–AuSPCE) | Electrochemical microfluidic biochip, including BP-SPCE with an OA aptamer | DPV | OA/mussels | 10–250 nM | 8 pM | [55] |
| Indium–tin-oxide electrode (ITO) | Electrochemiluminescence (ECL) aptasensor supported by magnetic graphene oxide (M-GO | ECL/CV | OA/mussels | 0.01–10 ng mL−1 | 4 pg mL−1 | [57] |
| AuSPE | Electrochemical aptasensor based on aptamer-complementary strands of aptamer complex forming a π-shape structure on the surface of the electrode and exonuclease I (Exo I) | DPV | AFB1/human serum, grape juice | 7–500 pg mL−1 | 2 pg mL−1 | [64] |
| AuSPE | Electrochemical immunosensor utilizing a competitive assay format | DPV | OTA and AFM1/red wine, milk | - | OTA 15 ng mL−1
AFM1 37 ng mL−1 |
[65] |
| SPCE | Magnetically assembled aptasensor for label-free determination of AFB1 employing a disposable screen-printed carbon electrode (SPCE) covered with polydimethylsiloxane (PDMS) film as the micro electrolytic cell | EIS | AFB1/peanuts | 20–50 pg mL−1 | 15 pg mL−1 | [66] |
| GO–PAA | Aptasensor employing PAA modified with GO and an aptamer of AFB1 | Amperometry | AFB1/no real samples | 1–20 ng mL−1 | 0.13 ng mL−1 | [67] |
| SPCEs | Aptasensor using a competitive format and modified screen-printed electrode | DPV | AFB1/maize flour | Dose–response curve 0.1–10 ng mL−1 | 0.086 ng mL−1 | [68] |
| AuE | Aptasensor having methylene blue (MB) as redox tag | SWV | AFB1/white wine | 2 nM–4 μM | 2 nM | [69] |
| Screen-printed bipolar electrode (BPE) | BPE-ECL aptasensor | ECL | AFB1/rice, wheat, corn, sorghum, barley, and buckwheat grains | 0.1–100 ng mL−1 | 0.033 ng mL−1 | [70] |
| GCE | Biosensor for AFB1 and ZEN using Escherichia coli as biorecognition element | CA | AFB1 and ZEN/peanut and corn oil | AFB1 0.01–0.3 mg mL−1
ZEN 0.05–0.5 mg mL−1 |
AFB1 1 ng mL−1
ZEN 6 ng mL−1 |
[71] |
| AuE | Immunosensor based on DNA tetrahedron-structured probe (DTP), obtained from the conjugation between DNA tetrahedron nanostructures and HRP -labeled AFB1 monoclonal antibody | DPV | AFB1/rice, wheat, corn, sorghum, barley, and buckwheat grains | 0.05–20 ng mL−1. | 0.033 ng mL−1 | [73] |
| LbL-GCE | Aptasensor assembled via layer-by-layer deposition of differently charged layers onto GCE. The AFB1 aptamer was immobilized onto the negatively charged layer |
EIS | AFB1/oil and soy sauce | 0.001–0.10 ng mL−1 | 0.002 ng mL−1 | [74] |
| AuNPs–GO–PABA–GCE | Immunosensor where AFB1 antibodies are linked to AuNPs–GO–PABA nanocomposite, deposited on GCE | EIS | AFB1/vegetable oils | 0.01–1.0 ng mL−1; 1–25 ng mL−1 | 0.001 ng mL−1 | [75] |
| AuE | Aptasensor where AFB1 aptamer is immobilized onto MCH layer self-assembled on AuE | SWV | AFB1/wine, milk, corn flour | 8 pM–25 nM; 25 nM–3 μM | 6 pM | [76] |
| MBs–SPCEs | Electrochemical magnetoimmunosensor involving magnetic beads (MBs) and disposable carbon screen-printed electrodes (SPCEs) | Amperometry | FB1/beer | Nonlinear calibration curves performed | 0.33 mg L−1 | [80] |
| AuNPs–PPy–rGO–SPCEs | Immunosensor using AuNPs–PPy–rGO nanocomposite as a platform for immobilizing anti-toxin antibody | DPV | FB1, DON/corn | FB1 0.2–4.5 ppm; DON 0.05–1 ppm | FB1 4.2 ppb; DON 8.6 ppb | [81] |
| NanoMIPs–PPY–ZnP–Pt | Chemosensor based on nano imprinted polymer nanoparticles (nano MIPs) immobilized | DPV, EIS | FB1/maize flour | 1 fM–10 pM | EIS 0.7 fM; DPV 0.03 fM | [82] |
| SPCE | Label-free electrochemical impedimetric aptasensor based on the diazonium-coupling reaction mechanism for the immobilization of anti-OTA aptamer at SPCEs | EIS | OTA/cocoa beans | 0.15–2.5 ng mL−1 | 0.15 ng mL−1 | [85] |
| AuE | Aptasensor based on the modified gold electrode with conductive polypyrrole layer covalently bound to polyamidoamine dendrimers of the fourth generation (PAMAM G4), where the OTA aptamer was immobilized | EIS | OTA/wine | - | 2 ng L−1 | [86] |
| SPCE | Competitive aptasensor where biotin-labeled and free OTA compete to bind with immobilized aptamer onto the surface of a screen-printed carbon electrode (SPCE) | DPV | OTA/cocoa beans | 0.15–5 ng mL−1 | 0.07 ng mL−1 | [87] |
| Au thin-film single electrodes | Impedimetric label-free immunosensor using two antibody immobilization methods (oriented, including protein A/G and not oriented) | EIS | OTA/cocoa beans | Oriented 0.01–5 ng mL−1
Not oriented 5 × 10−3–0.05 ng mL−1 |
Oriented 0.01 ng mL−1
Not oriented 5 × 10−3 ng mL−1 |
[88] |
| Bismuth-coated glassy carbon electrode (BFE) | Aptasensor assembled by combining nanocomposites of gold nanoparticles (AuNPs) functionalized silica-coated iron-oxide magnetic nanoparticles (mSiO2@Au) and cadmium telluride quantum dots (CdTe QDs) modified graphene/AuNPs nanocomposites (AuNPs/CdTe) | SWV | OTA/no real samples | 0.2–4 ng mL−1 | 0.07 pg mL−1 | [90] |
| AuE | Label-free electrochemical OTA aptasensor based on the peroxidase-like activity of g-C3N4 nanosheet (g-CNNS) and its high affinity toward single-strand DNA | CV | OTA/red wines, juices, corns | 0.2–500 nM | 0.073 nM, | [91] |
| AuE | Signal-on electrochemical aptasensor for OTA assay based on DNA controlled layer-by-layer assembly of dual gold nanoparticle (AuNP) conjugates | DPV | OTA/wine | 0.001–500 ppb | 0.001 ppb | [92] |
| TGA–AuE | Electrochemical immunosensor based on self-assembling a 2-mercaptoacetic (TGA) monolayer on the surface of Au electrode to form the Au/TGA/bovine serum albumin (BSA)-OTA/anti-OTA monoclonal antibody composite probe | DPV | OTA/malt | 0.1–1.0 ng mL−1 | 0.08 ng mL−1 | [93] |
Abbreviations: AFB1: aflatoxin B1; AuE: gold electrode; AuNPs: gold nanoparticles; AuSPE: gold screen-printed electrode; BFE: bismuth-coated glassy carbon electrode; BPE: bipolar electrode; CA: chronoamperometry; CB: carbon black; CV: cyclic voltammetry; DPV: differential pulse voltammetry; EIS: electrochemical impedance spectroscopy; ECL: electrochemiluminescence; FB1 fumonisin B1; rGO: reduced graphene oxide; GO: graphene oxide; ITO: indium–tin-oxide electrode; lbL: layer-by-layer; MBs: magnetic beads; MIPs: molecularly imprinted polymers: m-GEC: magnetic graphite-epoxy composite; MWCNTs: multi-walled carbon nanotubes; OA: okadaic acid; OTA: ochratoxin; PANI: polyaniline; PAA: poly(anthranilic acid); PPY: polypyrrole; QDs: quantum dots; SPCE: screen-printed carbon electrode; STX: Saxitoxin; SWV: square-wave voltammetry; SWASV: square-wave anodic stripping voltammetry; TGA: 2-mercaptoacetic acid.