Nanoparticle That Optimizes Singlet Oxygen Detection  

Singlet oxygen (¹O₂) is a high-energy form of oxygen and its applications range from photodynamic therapy to biological assays. Tufts University investigator Samuel Thomas has developed a nanoparticle that optimizes the detection of ¹O₂ – an improvement that enables its ratiometric measurement and will extend its application to intracellular imaging. 

Features • high photon yield count • color emission • ratiometric response 

Applications • in vitro bioassays • intracellular imaging • high-resolution nanoscopy 

Problem 

¹O₂ based detection systems currently rely on fluorescent probes for detection and yield a low photon count, thus emitting a weak signal. ¹O₂  also behaves like a sensor, the signal of which diminishes after a short period of time. Moreover, fluorescent probes that respond to ¹O₂ are not suitable for in vivo use.

Solution 

Samuel Thomas’s nanoparticle technology responds uniquely to ¹O₂. In this configuration, the normal energy transfer from donor to acceptor particle is inhibited in the presence of ¹O₂. Consequently, while the light emission from the donor increases, the emission from the acceptor decreases over time. This enables a ratiometric and significantly accurate detection of ¹O₂. 

Competitive Advantage

Existing enzyme-based detection assays and current singlet oxygen–based assays are often single intensity technologies that result in less accurate readouts and lack an internal signal control. The ratiometric response in our technology address both these existing issues. Unlike a sensor, this signal behaves more like a dosimeter – building up over time. 

Applications

This is an excellent opportunity for companies seeking to improve accuracy in quantitative ¹O₂ bioassay products to measure
• in vivo oxidation events and oxidative stress
• protein phosphorylation, cell signaling, and biomarkers 

This technology allows for the development of the following applications for the first time:
• Use of singlet oxygen in intracellular imaging assays
• Improvements on detectable markers used in high-resolution nanoscopy

Intellectual Property

US Publication No. 2018-0036434 (February 8, 2018)

Tufts University Invention T002125

Licensing Contact

John Cosmopoulos
john.cosmopolous@tufts.edu