Heavy metals enter the environment due to increasing industrial activities, which undermines the global sustainability. For instance, heavy metals are released from nanomaterials during production, transport and use of nanomaterials. Heavy metals such as mercury and lead are highly toxic and persistent contaminants that are not biodegradable and thus are retained in the ecosystem. Heavy metals accumulate in vital organs and cause human illness and dysfunction, posing a threat to human health, animals, plants, and the planet itself. Therefore, there is a strong incentive to develop convenient, cost-effective and field-deployable sensors for monitoring heavy metals in the environment. The objective of this project is to develop an optofluidic chip for multiplexed detection of heavy metals (Hg, Pb and g) in natural water. Three nanostructured fluorescent sensors will be developed for detection of Hg, Pb and Ag, respectively. A prototype optofluidic chip will be designed to integrate three fluorescent sensors with the sample pretreatment units and the fluid controls into a single chip. The performance of the integrated optofluidic chip will be tested with real-world water samples in terms of the limit of etection, sensitivity, selectivity and assay time.
Intellectual Merit : The proposed optofluidic chip synergistically integrates multiples nanostructured fluorescent sensors with microfluidics into a single chip to achieve a number of distinct advantages. First, the on-chip sample digestion unit will release free metal ions from the metal-organic complexes in natural water. Second, the on-chip capture cell will separate the metal ions from the real-world sample matrix, and pre-concentrate the metal ions prior to sensing. Third, the single optofluidic chip is capable of measuring multiple metals. Fourth, the inorganic nanoparticle-based fluorescent assay eliminates the photo-bleaching problem that is usually associated with organic dye fluorophores. Fifth, the portable optofluidic chip is expected to be able to directly measure the heavy metal in natural water.
Broader Impacts : Implementation of this project will result in a prototype portable optofluidic chip that can be used for on-site measurement of heavy metals in drinking water and in the aquatic environment without the need of prior sample digestion in a centralized lab. The data obtained will help the assessment of the environmental impact of heavy metals. The knowledge obtained will reduce the risk of the environmental exposure to heavy metal pollutants. The partnership formed between the university and the industry will greatly shorten the cycle of research, development and commercialization of new technology. The investigators plan to integrate the education activities into the research to stimulate the interest of students in the fields of science, technology, engineering and mathematics (STEM). The results obtained from the project will be used to create the course modules for both graduate and undergraduate courses. The investigators will recruit both graduate and undergraduate students, including underrepresented groups, to conduct research. The students will be trained not only in the academic environment but also in the industrial setting. The formation of the university-industry group will enhance the research and education infrastructure by sharing the resources and by training students and staff in both the sites. During the project period, both the university and the industrial company will host academic and industrial seminars presented by researchers and students from both the organizations, which will facilitate the fusion of knowledge between university and industry.
