Modified Organosilica Core–Shell Nanoparticles for Stable pH Sensing in Biological Solutions

• DOI: 10.1021/acssensors.8b00034
• Publication Date: 2018-04-10T16:37:18Z
• Authors: Kye J. Robinson; Gabriel T. Huynh; Betty P. Kouskousis; Nicholas L. Fletcher; Zachary H. Houston; Kristofer J. Thur...; Simon R. Corrie
• Keywords: Nanosensor

Continuous monitoring using nanoparticle-based sensors has been successfully employed in complex biological systems, yet the still suffer from poor long-term stability partially because of scaffold materials chosen to date. Organosilica core-shell nanoparticles containing a mixture covalently incorporated pH-sensitive (shell) and pH-insensitive (core) fluorophores is presented as continuous pH sensor for application media. In contrast previous studies focusing on similar materials, we sought investigate characteristics (dynamic range, sensitivity, response time, stability) function material properties. The ratio fluorescence intensities at specific wavelengths was found be highly sensitive over physiologically relevant range (4.5-8) with time <100 ms, significantly faster than that previously reported times silica-based particles. Particles produced stable, pH-specific signals when stored room temperature more 80 days. Finally, demonstrated nanosensors monitored bacterial culture 15 h changes skin mouse cadavers could also observed via vivo imaging following subcutaneous injection. understanding gained linking properties will inform next generation optical continuous-monitoring applications.