DENDRITIC OXYGEN SENSOR WITH TWO-PHOTON ABSORBING ANTENNA

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。将磷光猝灭技术与多光子激光扫描显微镜相结合，可以实现亚微米级空间分辨率的三维氧成像。然而，传统上用于生物氧传感的铂、钯基磷光染料表现出极低的双光子吸收(2PA)截面。利用已知的与卟啉相连的大的双光子截面的发色团，我们正在研究在光激发和随后的发色团和卟啉之间的能量转移后产生高磷光产量的可能性。这种络合物对于使用磷光而不是荧光的单分子(SM)研究是非常可取的。到目前为止，由于信号电平低，磷光在SM技术中的使用相当有限。磷光依赖氧猝灭是一种灵敏的测量分子氧的方法。我们提出的络合物可以在利用体内成像技术测量组织中的分子氧方面发挥关键作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Imaging oxygen in 3D with sub-micron spatial resolution can be made possible by combining phosphorescence quenching technique with multiphoton laser scanning microscopy. However, Pt and Pd porphyrin-based phosphorescent dyes, traditionally used as phosphors in biological oxygen sensing, exhibit extremely low two-photon absorption (2PA) cross-sections. Using chromophors with large known two photon cross sections linked to porphyrins, we are investigating the possiblity of generating high phosphorescence yields after photoexcitation and subsequent energy transfer between chormophor and porphyrin. Such complexes would be highly desirable for single molecule (SM) studies employing phosphorescence instead of fluorescence. Up to this point, the use of phosphorescence is quite limited in SM techniques due to the low level of signal. Oxygen dependent quenching of phosphorescence is a sensitive method for measuring molecular oxygen. Our proposed complexes could play a key role in measuring molecular oxygen in tissue employing an imaging technique in vivo.