title: An SPR based sensor for allergens detection.
abstract: A simple, sensitive and label-free optical sensor method was developed for allergens analysis using α-casein as the biomarker for cow's milk detection, to be used directly in final rinse samples of cleaning in place systems (CIP) of food manufacturers. A Surface Plasmon Resonance (SPR) sensor chip consisting of four sensing arrays enabling the measurement of samples and control binding events simultaneously on the sensor surface was employed in this work. SPR offers several advantages in terms of label free detection, real time measurements and superior sensitivity when compared to ELISA based techniques. The gold sensor chip was used to immobilise α-casein-polyclonal antibody using EDC/NHS coupling procedure. The performance of the assay and the sensor was first optimised and characterised in pure buffer conditions giving a detection limit of 58ngmL-1as a direct binding assay. The assay sensitivity can be further improved by using sandwich assay format and amplified with nanoparticles. However, at this stage this is not required as the detection limit achieved exceeded the required allergens detection levels of 2µgmL-1for α-S1-casein. The sensor demonstrated good selectivity towards the α-casein as the target analyte and adequate recoveries from CIP final rinse wash samples. The sensor would be useful tool for monitoring allergen levels after cleaning procedures, providing additional data that may better inform upon wider food allergen risk management decision(s) that are made by food manufacturer. In particular, this sensor could potentially help validate or optimise cleaning practices for a given food manufacturing process.
authors: Cranfield University, Advanced Diagnostics and Sensors Group, Cranfield, Bedford, MK43 0AL UK.
authors: J
authors: J
authors: Ashley
authors: Cranfield University, Advanced Diagnostics and Sensors Group, Cranfield, Bedford, MK43 0AL UK.
authors: M
authors: M
authors: Piekarska
authors: Cranfield University, Advanced Diagnostics and Sensors Group, Cranfield, Bedford, MK43 0AL UK.
authors: C
authors: C
authors: Segers
authors: University of Manchester, School of Chemical Engineering and Analytical Science, Oxford Road, Manchester, M13 9PL UK.
authors: L
authors: L
authors: Trinh
authors: University of Manchester, School of Chemical Engineering and Analytical Science, Oxford Road, Manchester, M13 9PL UK.
authors: T
authors: T
authors: Rodgers
authors: Safety and Environmental Assurance Centre, Colworth Science Park, Unilever plc, Sharnbrook, Bedford, MK44 1LQ UK.
authors: R
authors: R
authors: Willey
authors: Cranfield University, Advanced Diagnostics and Sensors Group, Cranfield, Bedford, MK43 0AL UK. Electronic address: i.tothill@cranfield.ac.uk.
authors: I E
authors: IE
authors: Tothill
mesh_terms: D000485:Allergens / Q000032:analysis*; D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry*; D002364:Caseins / Q000032:analysis*; D002417:Cattle; D006046:Gold / Q000737:chemistry; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D000485:Allergens; D055910:Antibodies, Immobilized; D002364:Caseins; D006046:Gold
keywords: Allergens; Antibody; Cleaning in place systems (CIP); Milk proteins; SPR; Surface plasmon resonance