Development of a Possible Paper Based Detector of Pure Food Allergen for Possible Onsite Detection
Currently, available food allergen detection methods are a mixture of cumbersome, time-consuming, complicated, and expensive. Lack of technology for simple allergen detection for food samples could potentially lead to anaphylactic shock in the consumer by cross-contamination. There is a need for techniques that is rapid, on-site, cost-effective, disposable, highly sensitive, and accurate to identify these molecules urges the development of a point-of-care device. The aim of this work was to develop a microfluidic paper-assisted analytical device (μPAD) using hydrophobic channels, set by a wax printer on filter paper, and nanomaterials to identify the allergens arachin (Ara h 1) for peanuts, β-lactoglobulin (β LG) for milk, and tropomyosin (Pen a 1) for shrimp and other shellfish presence. Polymer Nanoparticles (PnP) and gold nanoparticles (AuNP) were investigated and exploited for the development of assays, which could meet the need for rapid onsite detectors. We utilized aptamers as the primary biorecognition element in conjugation with their particular interaction with graphene oxide (GO) in their unbound state. The developed μPAD used AuNP to create a colorimetric system which has enough sensitivity to detect in the allergens present down to the nanogram range (allergens measured from 25 nM – 1000 nM with an LoD of 7.8 nM, 12.4 nM and 6.2 nM for peanut, milk and shrimp allergens respectively), in contrast to the microgram range of commonly used enzymatic immunoassays. The simple color indicator, varying from uncolored to pink in the presences of allergens allows utilization of the readout without the need for highly specific equipment or training. Alternatively, the results can be quantified by taking a picture and measuring the color. This presented μPAD can provide results in real time and has the potential to become a rapid, low-cost, and accurate portable point-of-care device for people to avoid cross-reactivity of food-borne allergens. Further investigation into PnP nanomaterial platforms may yield better, cheaper alternatives for use with μPADs.