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 (<10 minutes), simple operation and low cost (<$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.
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