VIP Projects

Microplastics (MPs) are plastic fragments smaller than five millimeters, existing in various mediums including drinking water, food, and within the human body. Previous research links the ingestion of microplastics to serious health issues such as hormonal imbalances, infertility, and developmental abnormalities due to toxic phthalate esters (PEs), bisphenols, and heavy metals present in the MPs. Some of the most common MPs found in the environment include polystyrene (PS) and polyvinyl chloride (PVC) microplastics, accounting for over 36 million tons of waste in 2019. Despite all of this waste, current detection methods for these MPs in waterways are expensive, require extensive laboratory equipment and training, take a significant amount of time to produce results, lack sensitivity, and are overall inaccessible. This has resulted in a critical lack of MP tracking, making it difficult for preventative policies to be put into place had these metrics been known. In our study, we have designed an aptamer-based, enzyme free, colorimetric screening tool that can be used as a field-ready sensor to detect PVC and PS microplastics within drinking water. The signal generated by the aptamer adsorbing onto a microplastic is amplified using a Hybridization Chain Reaction (HCR) and then visualized with a colorimetric shift caused by the aggregation of gold nanoparticles (AuNPs). Thus, we provide a practical approach for microplastic detection and tracking, supporting efforts to reduce ingestion into the human body before serious health issues develop.

Dengue fever, caused by the dengue virus (DENV), remains one of the most prevalent mosquito-borne diseases worldwide, significantly impacting tropical regions. Due to the existence of multiple serotypes (DENV 1-4), secondary infection with a different serotype significantly increases the risk of severe dengue, making serotype differentiation important. Expanding mosquito habitats due to climate change and rapid urbanization have increased global transmission, particularly in low-resource regions where laboratory-based diagnostics are limited. Current gold-standard methods, such as reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), require specialized equipment and centralized facilities, creating a need for accessible point-of-care diagnostics. This project aims to develop a low-cost, portable diagnostic tool that utilizes reverse transcription loop-mediated isothermal amplification (RT-LAMP) with a multiplex lateral flow assay (LFA) to detect and differentiate all four DENV serotypes. The amplified products will then be detected using streptavidin-coated gold nanoparticles (AuNPs) and DNA capture probes immobilized by high salt concentration on multiplex LFA strips, eliminating the need for antibodies. Initial testing with synthetic DNA samples demonstrated successful amplification of the DENV-2 serotype at 46,671 copies/reaction using colorimetric in around 45 minutes. Future work will include optimizing LAMP sensitivity and further validation with Fluorescent LAMP to determine the absolute limit of detection. A portable heating device has already been 3D printed to enable instrument-free amplification. This diagnostic tool has the potential to improve early diagnosis and outbreak monitoring in resource-limited settings.