Silica-coated ruthenium-complex nanoprobes for two-photon oxygen microscopy in biological media
Abstract
Multiphoton microscopy (MPM) allows for three-dimensional in vivo microscopy in scattering tissue with submicron resolution and high signal-to-noise ratio. MPM combined with fluorescence lifetime measurements further enables quantitative imaging of molecular concentrations, such as dissolved oxygen, with the same optical resolution as MPM, in vivo. However, biocompatible oxygen-sensitive MPM probes are not available commercially and are difficult to synthesize. Here we present a simple MPM oxygen imaging probe compatible with aqueous biological media based on a water-soluble ruthenium-complex nanomicelle. By adding a layer of silica shell to the nanomicelle assembly, oxygen sensitivity and probe stability in biological media increases dramatically. While uncoated probes are unusable in the presence of serum albumin, photophysical characterization shows that the silica coating enables quantitative oxygen measurements in biological media and increases probe stability by more than an order of magnitude.
Yide Zhang
Postdoctoral Fellow
My research is interdisciplinary and focused on developing new types of optical imaging techniques that could advance the work of other researchers and medical personnel in a wide variety of fields. Currently, I am developing next-generation photoacoustic and ultrafast imaging techniques that can observe biological and physical phenomena that are too fast to be imaged with existing methods. The observation of the ultrafast phenomena could provide a better understanding of the fundamentals of life and physical sciences. I am also developing novel quantum imaging approaches that can investigate biological organisms with an imaging performance that cannot be achieved using classical optical imaging. In my free time, I enjoy cooking, hiking, cycling, and traveling.