Magneto immunosensor for gliadin detection in gluten-free foodstuff: Towards food safety for celiac patients

Gliadins in Foods and the Electronic Tongue

“…Mairal et al (2009) developed a microfluorimeter with a disposable polymer chip with a gliadin detection limit of 4.1 ng/mL, by detecting the emission of a fluorophore-labeled monoclonal antigliadin antibody upon excitation with light. Laube et al (2011) developed an electrochemical magneto immunosensor, coupled or not to ELISA, allowing the quantification of gliadin or small gliadin fragments in natural or pretreated food samples with detection limits ranging from 1.2 to 24.2 ng/mL (depending on the food matrix). Chu and Wen (2013) developed a sensitive liposomal fluorescence immunoassay with immunomagnetic beads for the detection and quantification of gliadin in gluten-free foods with a detection limit of 0.6 mg/mL (or ppm), although slight cross-reactions with barley and rye were found.…”

Electrochemical Affinity Biosensors in Food Safety

“…Most of the approaches employ sandwich-type configurations implemented onto carboxylic acid-modified magnetic beads (HOOC-MBs) and SPEs to perform an amperometric transduction [97][98][99]103,104]. These approaches demonstrated very attractive performance and successful applicability to the analysis of real samples such as spiked skimmed milk and beer [94], milk [97,99], infant formulations [104] food extracts [99,103] and saliva [100]. Among them it is worth to highlight the immunosensor reported recently by Ruiz-Valdepeñas Montiel et al [103] for the rapid and simultaneous detection of Ara h 1 and Ara h 2 (the two major peanut allergenic proteins).…”

“…Regarding immunosensors, particularly useful biosensors involving the use of functionalized MBs have been described for the determination of gliadin [94], β-lactoglobulin [97], ovalbumin [98], Ara h 1 [99,103], Ara h 2 [103] and α-lactalbumin [104]. Most of the approaches employ sandwich-type configurations implemented onto carboxylic acid-modified magnetic beads (HOOC-MBs) and SPEs to perform an amperometric transduction [97][98][99]103,104].…”

“…Monitoring of the antigen-antibody interaction using DPV in the presence of [Fe(CN) 6 ] 4−/3− , allowed a LOD of 5 × 10 −8 g·mL −1 to be achieved. Immunosensors for β-lactoglobulin [94] and OVA [96] were developed by electro-grafting an aryl diazonium salt organic film on graphene-modified SPCEs. The capture antibody was covalently immobilized using EDC/NHS chemistry or glutaraldehyde on the carboxyphenyl [96] or nitrophenyl [95] groups of the film grafted onto the graphene electrodes by electrochemical reduction of the in situ generated diazonium salt.…”

“…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].…”