Ph.D Candidate, Mechanical Engineering, Xi’an Jiaotong University M.S., Mechanical Engineering, Xi’an Jiaotong University, 2014 B.S. Mechatronic Engineering, Chang’an University, 2013
Title: “Ordered Ag@MOF Core-shell Nanostructures for SERS-based Chemical Analysis” Abstract: A large number of poisonous chemicals, such as PFOA, PFOS, and mercury ions, are mandated to be controlled in drinking water with their permissible concentrations below parts-per-billion (ppb). In this context, pre-concentration is a necessary step preceding detection. Apart from their selective absorption ability, metal-organic frameworks (MOFs) have an extraordinarily large internal surface area, which can be used for extraction. In terms of detection methods, Raman spectroscopy is a powerful non-invasive chemical detection technology characterized by portability, accuracy, and speed. In addition, concentrations in the ppb range and below can be detected with surface enhanced Raman scattering (SERS). As a result, a combination of the SERS and extraction method may allow the detectable concentration limit in the parts-per-trillion (ppt) range. This research is devoted to the design and optimization of Ag@MOF core-shell nanostructures for detection of chemicals in ppt level. Lyophobic ZIF-8 serves as the extractor of the chemical of interest and Ag as the plasmonic particles for SERS. Additionally, to obtain the lowest detectable concentration limits and good selectivity towards metal ions, post-processed MOFs (e.g., MIL-53- NH2, MOF-808 with EDTA and dithizone) will be examined. This project seeks for optimum structural design and controllable arrangement of Ag@MOF nanostructures towards low-cost, sensitive and rapid SRES-based chemical detection in solution.