Detection of the peanut allergen Ara h 6 in foodstuffs using a voltammetric biosensing approach

Abstract

A voltammetric biosensor for Ara h 6 (a peanut allergen) detection in food samples was developed. Gold nanoparticle-modified screen-printed carbon electrodes were used to develop a sandwich-type immunoassay using twomonoclonal antibodies. The antibody-antigen interaction was detected through the electrochemical detection of enzymatically deposited silver. The immunosensor presented a linear range between 1 and 100 ng/ml, as well as high precision (inter-day RSD ≤9.8 %) and accuracy (recoveries ≥96.7 %). The detection and quantification limits were 0.27 and 0.88 ng/ml, respectively. It was possible to detect small levels of Ara h 6 in complex food matrices.

Simultaneous Determination of the Main Peanut Allergens in Foods Using Disposable Amperometric Magnetic Beads-Based Immunosensing Platforms

“…Figure 6 shows as the dual immunosensor was able to discriminate samples contaminated with 0.0001%-0.01% peanut through Ara h 2 detection whereas samples contaminated with 0.01%-1.0% peanut could be identified by means of Ara h 1 detection. The ability to detect clearly 0.0001% (1.0 mg¨kg´1) peanut improves in a factor of 500-1000 the lowest detectable trace peanuts concentration reported previously by other authors based on Ara h 1 determination, 0.05 [14] and 0.1% [12,13]. This enhanced sensitivity means a major comparative advantage taking into account the serious public health problem that the contamination degree with peanuts of commercial food samples, whether fraudulent or accidental, may cause in sensitive individuals.…”

Impedance Biosensor Incorporating a Carboxylate-Terminated Bidentate Thiol for Antibody Immobilization

“…Recently biosensors based on a variety of different methods, including electrochemical impedance spectroscopy (EIS), have been investigated for rapid, inexpensive and multiplexed detection of food allergens. 24 The technical challenges for applications of impedance biosensors have been recently reviewed, 7 and include the stability and reproducibility of biomoelecular immobilization at a conductive electrode surface, non-specific adsorption in complex media, and the increased difficulty of AC impedance detection relative to DC electrochemistry. The current report focuses on the first challenge, improving the stability of biomolecular immobilization at Au electrodes, which are the most commonly employed substrates.…”

Electrochemical Affinity Biosensors in Food Safety

“…They are classified according to the type of used bioreceptor. The bioreceptors most commonly used are specific antibodies [93][94][95][96][97][98][99][100][101][102][103][104], single-stranded DNA molecules [105][106][107][108], aptamers [109][110][111][112], and other affinity receptors like lectins [113] and peptides [114]. The affinity reaction between these bioreceptors, which are immobilized onto electrodes or solid supports like magnetic beads (MBs), and the target allergen has been monitored using (chrono)amperometry [68,94,97,99,[101][102][103][104]109], voltammetry [93,95,96,98,102,103,106,107,[112][113][114] and electrochemical impedance spectroscopy [105,110,111].…”

“…Both immunosensors provided LODs in the low pg·mL −1 level (0.85 and 0.83 pg·mL −1 for β-lactoglobulin and OVA, respectively) and demonstrated applicability to the analysis in real food samples (cake, cheese snacks and sweet biscuits). More recently, Alves et al developed sandwich immunosensors for Ara h 1 [100] and Ara h 6 [101] determination onto AuNPs-SPCEs monitoring electrochemically the antibody-antigen interaction through stripping analysis of enzymatically (using alkaline phosphatase) deposited silver. These methods provided LODs of 0.27 and 3.8 ng·mL −1 for Ara h 6 and Ara h 1, respectively, and were successfully applied to complex food matrices.…”

“…In addition, given the sensitivity required for some allergens detection, many biosensor devices with improved sensitivity based on the use of nanomaterials, such as QDs [115], AuNPs [93,100,101,[106][107][108], MWCNTs [93] and graphene [95,96,106] have been developed. Worth to mention also the increasing tendency to fabricate these electrochemical biosensors onto screen-printed electrodes (SPEs) [85,[95][96][97][98][99][100][101][102][103][104]107,109,112,113] since they are suitable to be fabricated with different materials, to be drawn in diverse geometries and multiplexed formats and Recently, Sugawara et al [116] developed an electrochemical biosensor to detect ovalbumin (OVA) by adsorbing a specific peptide probe (peptide-1) conjugated with the electroactive daunomycin on a GCE.…”