The increasing rise in allergy prevalence has led to a growing demand for portable allergen testing devices. Food allergens, which can lead to fatal immune reactions, are especially complicated to avoid due to cross contamination and food mislabeling, as seen with many types of seafood. Instances of seafood mislabeling and inauthenticity also impacts consumers financially when cheaper options are passed off as more rare and expensive fish. Atlantic salmon is one of the most commonly used fish for this type of fraud. Devices to detect allergens and/or authenticity must be easy-to-use, quick, and require little to no dangerous reagents for the regular consumer. While there are some commercial devices on the market for peanut and gluten detection, they are costly and do not appear to be very accurate or sensitive. Our prior work showed a proof of concept for a one-pot amplification-detection method with recombinase polymerase amplification that allowed for a reaction to occur at a fixed temperature and with no expensive laboratory equipment. Currently, I am developing fluorescence-based polymerase chain reaction and recombinase polymerase amplification assays that can differentiate Atlantic salmon from other types of salmon. To further develop this technology into a consumer-friendly allergen detection and seafood authentication device, I plan on adapting the assay into an electrochemical format, allowing for simplified readouts of the results. The results from this assay would be able to be displayed on easily accessible electronic devices, such as a smartphone or laptop. In its final form, this project will demonstrate a portable heating device with a classification assay that would be able to detect the presence of Atlantic salmon without laboratory equipment.

Chloramphenicol (CAP) is a synthetic antibiotic used to treat various bacterial infections in animals and humans. However, case studies and clinical trials have revealed that CAP can induce severe blood disorders, genotoxicity, and carcinogenic effects. Consequently, in 1997, the United States and several other countries prohibited its use in food-producing animals and imposed strict regulations on its application in human healthcare. Despite regulations, CAP remains prevalent in food, especially in imported seafood like shrimp, posing a risk to human health. To address this issue, we aim to develop a CAP contamination-detection assay using two engineered DNA strands: a CAP-specific aptamer and a blocker. Using NUPACK, a Python package for thermodynamic analysis of nucleic acids, we created scripts to design, select, and evaluate candidate DNA strands from our sequence library. We are developing a two-phase assay to assess their specificity and sensitivity to CAP. In the first phase, blockers are tagged with a fluorophore, and aptamers are conjugated with biotin and a corresponding quencher. These sequences are incubated in streptavidin-coated wells, and the aptamer-blocker separation is measured via fluorescence when aptamers more favorably bind to CAP. In the second phase, the released blockers are collected, amplified, and detected using recombinase polymerase amplification (RPA) with exonuclease III and target-specific probes. Unlike the first phase, the aptamers remain biotinylated with no fluorophore-quencher conjugation, as target-specific probes have their fluorescence mechanism. In the future, this assay will be streamlined and used in conjunction with point-of-care applications to detect other small molecules.