Development of a Novel Lateral Flow Immunoassay for Detection of Harmful Allergens Found in Dust

Abstract

Prior research has shown that specific allergens from house pests, including mice, dust mites, and cockroaches, can lead to worsened symptoms for asthmatic patients. These allergens can be found in indoor environments where dust collects, such as homes, schools, or hospitals. There currently is a need for an accurate, easy-to-use, inexpensive sensor that is capable of detecting and quantifying the amount of these allergens in samples of dust collected in these indoor environments. This sensor would help lead to treatment of pest problems in affected areas and allow for further study of the interaction between these allergens and health outcomes. To create this biosensor, a lateral flow assay has been developed. The developed system uses novel polymer-based materials created by electrospinning. The polymers used in this work include Cellulose Acetate (CA) and Polyvinylpyrrolidone (PVP). Electrospinning is a process where high voltages are used with a syringe pump to create a Taylor cone that sends a polymer jet onto a collector plate. This polymer jet collects on the collector plate as polymer nanofibers, which after aggregation with other nanofibers become a nanofibrous polymer mat. In our work, electrospun polymers have been functionalized for use in traditional portions of a lateral flow immunoassay testing strip. Antibodies encapsulated using polymer processing techniques, and antibodies immobilized onto electrospun polymer material allow for the traditional sandwich detection method when allergen is present. The sandwich detection method makes use of the binding of two antibodies, at different and non-inhibiting binding sites, to a single allergen to cause an observable and measurable color change when the allergen is present. An illustration of the sandwich detection technique is included as the abstract image. One of the antibodies must be immobilized, and the other must be optically labeled for the sandwich to produce a color change. We also have developed a wicking polymer using electrospinning to act as the backbone for our biosensor strips. This is a novel application of electrospun polymers for wicking, and we have worked to characterize and optimize the wicking properties of this material. The use of electrospinning to create functional polymers, which are biocompatible, inexpensive, and relatively safe, poses advantages over the materials typically used in literature, including nitrocellulose, which is a flammability hazard. This novel wicking material has high potential for future use in lateral flow assays and other biosensing techniques that make use of wicking materials. A collaborative group is working to create a phone application that will use the color produced by the strip when a sample is loaded to determine the amount of allergen in the sample and estimate the severity of the indoor environment’s pest problem. The combination of the optical sensor and phone app will enable quantitative measurement of harmful allergens in the dust sample. This will allow the user to take necessary action to remove pests and dust that is worsening asthma symptoms and related health outcomes. Future work in this project includes working to improve the sensitivity of the color change, which will require signal amplification techniques and analysis of different labeling methods. Additionally, the novel wicking material, allergen detection technique, and phone application could be modified to detect other biomolecules of interest for important health, environmental, or related fields. Figure 1