Multiplexed biosensor for personal wildfire exposure assessment

Summary/Abstract: Wildfire are becoming more frequently and severe due to climate change, resulting in growing exposures of major population to high level of benzene and polycyclic aromatic hydrocarbons from biomass-burning emissions. Wildfire exposure pose a serious threat to the health and the well-being of humans. Currently, assessment of personal exposure to wildfire is dependent on taking environmental samples and analyzing the samples using expensive analytical techniques, which cannot adequately represent personal exposure due to the temporal and spatial variation of the metabolite concentrations. Biological detection of biomarkers has great potential to overcome the limitation of conventional techniques and provides accurate measurements of personal exposure levels. In this SBIR project, DL ADV-Tech proposes to develop an advanced europium-nanoparticles enhanced time-resolved fluorescent (TRF) immunoassay biosensor which provides extremely sensitivity (pg/ml level), short turnaround time (lt10 minutes), simple operation and low cost (lt$5 for each test) for non-invasively analyzing wildfire exposure in urine samples. A major significance of this proposed approach is the ability to on-site and very accurately analyze low amount of biomarkers by leveraging our advanced nanomaterials signal amplification technique and multiplex sensing technique. The proposed biosensor includes a paper-based strip to simultaneously measure multiple metabolites, 2-naphthol (2-NAP), 1- hydroxypyrene glucuronide (1-OHPG) and S-phenyl mercapturic acid (S-PMA), where newly developed nanomaterial, europium (Eu)-based nanoparticles (YVO4:Eu) is introduced to achieve high sensitivity. A portable TRF reader will be equipped to quantify the concentrations of targets. We have demonstrated that using the advanced Eu-based nanoparticles as signal label, the proposed fluorescent immunoassay is expected to improve the stability, reliability and accuracy in detection of wildfire-associated biomarkers in urine. Incorporated with this innovative signal amplification strategy, the sensitivity of the proposed biosensor is expected to be significantly increased. Using the proposed biosensor, the measurement of personal wildfire smoke exposure biomarkers can be completed within 10 minutes and the detection limit can as low as 0.1 ng/ml. In this Phase I project of proof-of-concept, we will focus on the biosensor with two test zones that simultaneously quantify three urinary metabolites (2-NAP, 1-OHPG and SPMA). The proposed biosensor will be fabricated and validated, and the analytical 'figures of merits' of the biosensor will be established. In Phase II, the biosensor will be further optimized for on-site applications in real world conditions and scaled-up for detecting more biomarkers associated with wildfire exposure. This highly precise and truly portable TRF biosensor will provide a non- invasive, sensitive, simple, rapid, robust, and inexpensive assessment tool, which will revolutionize current biomonitoring technique for assessing personal exposure levels with shorter time and lower cost. 1