(Invited) Quantification of NO Concentration Via Changes in Single Walled Carbon Nanotube Fluorescence

Abstract

Nitric oxide (NO) is a reactive nitrogen species that is involved in both positive and negative processes in biological systems. Researchers have been unable to agree on the correlation between NO concentration and disease progression, possibly because of NO’s short half-life and the difficulty of determining concentration with current NO sensors. Single walled carbon nanotubes (SWNT), when wrapped in single-stranded (AT)15, act as a fluorescence sensor for NO. Unfortunately, the correlation between NO concentration and the SWNT’s fluorescence intensity has been difficult to determine due to the fact that the final SWNT fluorescence intensity does not directly correlate to NO concentration and an inability to immobilize the sensor without altering its properties. Through the use of a recently developed sensor platform, systematic studies have been conducted to determine the correlation between changes in SWNT fluorescence and NO concentration. The methods used to determine equations that convert SWNT fluorescence into NO concentration will be presented, providing a method to quantify extracellular NO concentration and a blueprint for the development of equations to transform changes in SWNT fluorescence into concentrations for other reactive species.