제목: 양자점의 바이오 응용: 암모니아 생산 및 항생제 내셩균 감염 치료

내용: he use of nanoparticles in biological applications has taken dynamically different phases. Efficient and relatively bleaching-free photoluminescence from semiconductor nanoparticles was considered to make the materials suited for bio-imaging. After a surge of research interest, however, the progress stalled. While marginal progress persists, the fundamental question of electron transfer from nanoparticles to biospecies poses both a challenge and an opportunity. The fertile opportunity space opens as we eye the biomedical applications, e.g., superbacterial killing for infected skin. In this talk, I will briefly discuss our strategy for the work on in vitro and in vivo studies of selective bacterial killing using nanoparticles as photoelectron donor.
For the next part of the presentation, I will talk about our progress on the nitrogen fixation in microorganisms to produce ammonia by incorporating inorganic semiconductor nanocrystals, also referred to as quantum dots (QDs), into genetically-engineered bacterial cells. Transformation of atmospheric nitrogen into ammonia is indispensable to the humanity, as global food production from intensive agriculture relies heavily on ammonia-based fertilizers. The Haber-Bosch process has enabled the revolution in the manufacture of fertilizers, spurring the growth of human population in the past century. However, the development has come at the expense of energy and environmental penalty: the nitrogen production via the Haber-Bosch process is energy-intensive, consuming up to 2% of the world’s energy output. Besides, hydrogen used in the Haber-Bosch process is obtained from the steam reforming of methane by and large, which accounts for significant CO2 emission. For this reason, a novel system for low-energy ammonia refinery is demanded for sustainable and environmentally benign nitrogen transformation. 
The QDs generate and transfer photo-generated electrons to Component I, the catalytic site of nitrogenase, in Azotobacter vinelandii (A. vinelandii) at an orders-of-magnitude higher rate (~1012 s-1 vs ~70 s-1 in wild-type nitrogenase). Light-driven control of QDs with large absorption cross-section will address the limitation of relatively low ammonia production rate (~119 NH3∙s-1) in nitrogen-fixing bacteria.