Table 1.
Electrochemical immunosensing methodologies reported since 2017 for the determination of food allergens and adulterants.
| Electrode | Methodology | Target Allergen/Adulterant (Food) | Detection Technique | Linear Range | LOD | Sample | Steps */Assay Time | Ref. |
|---|---|---|---|---|---|---|---|---|
| Allergens | ||||||||
| AuNPs-SPCE | Sandwich immunosensor involving a bDAb further conjugated with Strep-AP | Ara h 6 (Peanut) | LSV (3-IP+AgNO3) | 1–100 ng mL−1 | 0.27 ng mL−1 | Complex chocolate-based product containing peanut | 3/3 h starting from CAb- AuNPs-SPCE | [40,54] |
| SPCE | Sandwich immunoassay implemented onto HOOC-MBs involving the same Ab unmodified as capture and labeled with HRP as detector | Ovomucoid (Egg) | Amperometry (H2O2/HQ) | 0.3–25 ng mL−1 | 0.1 ng mL−1 | Eggs, wheat flour and baked bread | 1/30 min starting from CAb-HOOC-MBs | [44] |
| GCE | Crosslinking of gliadin on the surface of a collagen-modified GCE, catalyzed by transglutaminase and recognition with a specific anti-gliadin antibody | Gliadin (Gluten) | EIS [Fe(CN)6]3-/4- | 5–20 mg L−1 | - | - | 4/4 h | [55] |
| SWCNTs-Au-Cr deposited silicon wafer | Direct immunoassay onto and CAb covalently immobilized onto 1-PBSE-modified SWCNTs | Ara h 1 (Peanut) | LSV | 1–1000 ng mL−1 | 1 ng mL−1 | - | 1/30 min starting from the SWCNT-based biosensor | [56] |
| Au-SPEs (individual and array of 8 × SPEs) | Sandwich immunoassays implemented on the surface of Epoxy-MBs | Gliadin, Ara h1, Cor a 1, Casein, Ovalbumin/Gluten, peanuts, hazelnuts, milk, and eggs. | Chronoamperometry (H2O2/TMB) | - | Gliadin: 0.075 mg Kg−1 Ara h1: 0.007 mg Kg−1 Cor a 1: 0.089 mg Kg−1 Casein: 0.170 mg Kg−1 Ovalbumin: 0.003 mg Kg−1 | Bread, milk, cereal, cookie, ice cream, burger, salads with dressing, pizza, beer and gluten-free menu items from restaurants | 2/6 min starting from CAb-Epoxy-MBs | [21] |
| SPCE | Sandwich immunoassay implemented onto HOOC-MBs involving specific CAb and DAb and enzymatic labeling with an HRP-secondary Ab | Shrimp TPM (Shrimp) | Amperometry (H2O2/HQ) | Up to 218.7 ng mL−1 | 47 pg mL−1 | Raw and cooked shrimp and squid samples | 3/3 h starting from CAb-HOOC-MBs | [41] |
| CNFs/SPCE coupled to a paper immunoaffinity platform | Sandwich immunoassay implemented onto paper microzone | Gliadin (Gluten) | Amperometry (H2O2/HQ) | Up to 80 μg kg−1 | Gliadin: 0.005 mg Kg−1 | Flour samples (manioc, rice, gluten free, common wheat) | 2/15 min starting from CAb-paper | [42] |
| Adulterants | ||||||||
| SPCE and SP4CEs | Sandwich immunoassays implemented onto HOOC-MBs involving the same Ab unmodified as capture and labeled with HRP as detector | Bovine, Ovine and Caprine IgGs (Milk) | Amperomety (H2O2/HQ) | Bovine IgGs: 2.6−250 ng mL−1, Ovine IgGs: 2.7−250 ng mL−1, Caprine IgGs 2.2−250 ng mL−1 | Bovine IgGs: 0.74 ng mL−1, Ovine IgGs: 0.82 ng mL−1, Caprine IgGs 0.66 ng mL−1 | Colostrum, raw, pasteurized and UHT milk samples | 1/30 min starting from CAb-HOOC-MBs | [43] |
AP: alkaline phosphatase; AuNPs: gold nanoparticles; CAb: capture antibody; CNFs: carbon nanofibers; DAb: detector antibody; EIS: electrochemical impedance spectroscopy; GCE: glassy carbon electrode; HQ: hydroquinone; HRP: horseradish peroxidase; 3-IP: 3-indoxyl phosphate; LSV: linear square voltammetry; MBs: magnetic beads; 1-PBSE: 1-pyrenebutanoic acid succinimidyl ester; SPCE: screen-printed carbon electrodes; SP4CEs: four working screen-printed electrodes; SWCNTs: single-walled carbon nanotubes; TMB: 3,3′,5,5′-Tetramethylbenzidine; TPM: tropomyosin. * Number of steps involved in the determination other than detection and sample preparation.