Reactive oxygen species (ROS) play a central role in oxidative damage of biological systems and have been implicated in the ageing process and diseases such as cancer. J. C. Scaiano and colleagues from the University of Ottowa, Canada, report the synthesis of two new sensors developed to detect ROS. Professor Scaiano explains more about the sensors in the interview below.

1. Could you explain the significance of your article to the non-specialist? 

Today, free radicals derived from the metabolism of oxygen have been implicated in several diseases as well as in the aging process. To have a better understanding in the exact role played by free radicals in vivo, it is crucial to be able to map free radicals at cellular level. Recently, fluorescent sensors have received much attention since they provide an accurate and sensitive technique for the detection of free radicals in biological samples. While they have excellent contrast (i.e., a very large difference in signals between samples that have been or not exposed to free radicals); they lack of efficiency (i.e., only a small fraction of the initial sensor gives a detectable signal), and their exact mechanism of action towards free radicals is still unclear. The two sensors developed, ABFhd and dABFhd ('d' stands for dimethyl analogue, 'hd' for hydrogen donor) allowed us to clarify the mechanism of action of fluorescent sensors towards free radicals; and provided good indication for developing strategies for improving the efficiency of fluorescent sensors. 

2. What has motivated you to conduct this work? 

Our general interest in free radical chemistry and their implication in biology triggered our attention in understanding the exact mechanism of action of fluorescent sensors towards free radicals in order to develop a new generation of more efficient sensors. 

3. Where do you see this work developing in the future? 

From an application perspective, we believe that fluorescent sensors combined with high-resolution fluorescent microscopy are the key tools that in the future will provide important insights into intracellular processes involving free radicals. 

4. Are there any particular challenges facing future research in this area? 

Obtaining new "easy to prepare" fluorescent sensors with biological compatibility, high fluorescent quantum yield and high efficiency will face synthetic challenges. 

Joanne Thomson