Optical Sensors for Quantification of Intracellular Redox Potentials

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SELECTBIO

Redox signaling is important in determining cell fate decisions and plays a pivotal role in the pathology of diseases such as cancer and neurodegeneration. There are significant challenges in quantitatively measuring intracellular redox potentials, and in this presentation, I will introduce a new approach. This approach is based on the use of nanosensors which comprise molecules that sense the local redox potential, assembled on a gold nanoshell. Since the Raman spectrum of the sensor molecule changes depending on its oxidation state and since the nanoshell allows a huge enhancement of the Raman spectrum, intracellular potential can be calculated by a simple optical measurement. The nanosensors can be controllably delivered cells, without any toxic effects, allowing redox potential to be monitored in a reversible, non-invasive manner over a previously unattainable potential range encompassing both superphysiological and physiological oxidative stress. In this presentation, the concept, the reporter molecules and the technique will be introduced. Furthermore, I will discuss how we have used this approach to study the regulation of redox potential in apoptosis and have correlated redox potential changes with changes in caspase activity.