The primary objective of this research is to develop and demonstrate a novel sensor based on nanoparticle surface enhanced Raman scattering (SERS) and D-shaped fibers for chemical, biological, and environmental detection with emphasis on understanding both the fundamental principles and critical engineering issues underling the sensor design and operation. The sensor will be highly sensitive, molecular specific, reliable, label-free, non-invasive, inexpensive, easy to produce commercially using existing technologies, compatible with existing lasers and detectors, and applicable to a large number of molecules of interest. This is made possible by the unique sensor architecture based on a combination of D-shaped fibers and novel SERS substrates, where SERS provides the high sensitivity (106-1015 enhancement factor), molecular specificity, and applicability to a wide range of compounds, while the novel D-shaped fiber provides the compactness, reliability, low cost, and ease of production.
The proposed research approach to the compact SERS sensor is to deposit a layer of nanoparticle aggregates on top of the polished surface of a D-shaped fiber. Light propagating inside the fiber is coupled to the nanoparticle layer where SERS is employed to detect the sample. The development encompasses the combined expertise of the two PIs, Gu, who specializes in photonic materials and devices, and Zhang, who specializes in synthesis and optical properties of nanomaterials. The long-term goal is not only to develop a reliable and robust sensor that satisfies the above desired features but also to understand the fundamental and technical issues underling the design, fabrication, and operation of this sensor. The developed sensor will be tested in the detection of several important chemical and biological systems including glucose, proteins, DNA, and bacteria. It can also be useful for in situ detection of chemical warfare agents, explosives, food pathogens, toxins, and blood or tissue proteins.
The intellectual merit of the proposed research lies in a better understanding of both the fundamental and technical issues underling the design and development of nanophotonic devices such as chemical and biological sensors. Advanced sensors are urgently needed for national security, military, and civilian applications. The fundamental knowledge gained from this research will be useful to the design and development of other devices based on nanomaterials such as detectors, displays, lasers, and light emitting diodes.
The broader impact of this research is mainly in advancing nanoscience and nanotechnology, with emphasis on novel sensor technologies for detection of chemical, environmental, and biological agents. The society as a whole is expected to benefit tremendously from progress and breakthroughs in nanoscience and nanotechnology research. Novel sensing technology based on nanomaterials is a major and integral part of nanotechnology. This proposed research will lead to multidisciplinary education and training of students. As part of this research, the PI plans to have regular joint group meetings between the two groups and joint seminars among Chemistry, Physics, Biology, and EE. The training of students in the fast growing fields of nanoscience and nanotechnology is critical to maintain the competitive edge of the US in these fields.
