Speaker Bio

Yu Fang is a distinguished university professor of Shaanxi Normal University, Xi’an, China and an Academician of the Chinese Academy of Sciences. He is now serving as a member of the State Textbook Bureau, director of the expert group for emendation of the National Senior and Junior High School Chemistry Curriculum Standards, a member of the Executive Council of the Chinese Chemical Society, and the deputy director of the Discipline Committee of Applied Chemistry of the Chinese Chemical Society. He received his BSc, MSc and PhD from Shaanxi Normal University (Xi’an, China), Huazhong Normal University (Wuhan, China) and Lancaster University (Lancaster, UK), respectively. He worked as a research fellow for the School of Chemistry of Birmingham University in the early 1990s. He returned to China in 1998, and joined Shaanxi Normal University as a professor of physical chemistry and polymer science. His research interests include mainly: film-based fluorescent sensors, and functionality-led soft and dynamic systems, where emphases are given to the physical chemistry at the surfaces, interfaces and adlayers of the relevant systems. His effort in research was repaid with successful incubation of a high-tech company on chemical sensors in Shenzhen, China. He received three first class Science and Technology Award from the government of Shaanxi Province.

Abstract

Film-based fluorescence sensors (FFSs) have been well recognized as the most optimizing technique for trace analysis of hidden explosives, illicit drugs and volatile organic compounds after the invention of ion mobility spectrometry, which is the nowadays most widely applied technique for the measurements. The key components of the fluorescence technique are the sensing films and the relevant sensor structure. As for the structure of the FFSs, the most commonly found one is the wave-guide structure, which, however, suffers from a number of shortcomings, such as: (1) hard to be integrated, (2) not easy to perform active layer coating, and (3) highly limited in substrate variation. Moreover, the wave-guide-based structure is protected by patent laws of different countries, which largely limits their values for further studies. Accordingly, we developed a new kind of fluorescent sensor structure recently, the so-called ‘laminated structure’. In the design, the core components of the sensors, such as the light source, the photo-sensitive device and the fluorescence film-based device, are assembled coaxially. It is the 1D structure that allows to minimize the sensor, to vary the film substrate, and to perform film fabrication in a simple way. For film design and fabrication, we have proposed a number of new concepts and used them for the development of high-performance sensing films since the late 1990s. The concepts proposed include mainly: spacer-layer screening effect, spacer-layer enrichment effect, and side-chain effect etc.. In addition, single-layer chemistry strategy, molecular gel strategy and combinational design strategy have been employed to tune the adlayer structures of low-molecular weight fluorophore-based sensing films. Recently, self-standing, defect-free, highly smooth fluorescent nanofilms have been fabricated and used for FFSs. It is the establishment of the new concepts, the employment of the diverse strategies and the use of the hardware structure that allow us to have developed some commercialized FFSs.