Building an Imaging Toolbox: Nanosensors for Biological Discovery

New tools have the potential to unlock unexpected insights into biology. We are extending the toolbox for cellular imaging by developing an array of optical nanosensors for the measurement of ion and small molecule concentrations in vitro and in vivo. Each sensor is based on a polymeric platform and works by extracting the analyte of interest into the particle, creating a change in optical signal. Our sensors are easily tunable for dynamic range and extendable to new analytes, such as sodium, chloride, glucose, and neurotransmitters. In addition to creating novel probes, we are focused on the application of these nanosensors to solving biological problems. First, we are creating “tattoo” for monitoring pharmacokinetic profiles of drugs in vivo. Our lithium-sensitive sensors can be injected into the dermal layer of the skin and monitored semi-continuously to obtain real-time drug concentrations. Second, we are using nanosensors for monitoring neurotransmitter release and ion signaling in neural tissue slices. Our advantage is the ability to image multiple analytes with both temporal and spatial resolution. In particular, we have demonstrated that a new type of sensor, which contains quantum dots in a polymer-free sensor is selective for potassium and photostable for cellular imaging. Ultimately, by combining advanced imaging techniques with our array of nanosensors, we plan to merge our two biological applications in order to image chemical dynamics at a greater depth in vivo.

Boston, Massachusetts, USA - October 29, 2010 - Heather Clark, Associate Professor of Pharmaceutical Sciences in Bouve College of Health Sciences at Northeastern University. PHOTO: Mary Knox MerrillDr. Heather Clark is a Professor and Vice Chair of the Department of Pharmaceutical Sciences at Northeastern University. Her research focuses on the development of fluorescent nanosensors for in vitro and in vivo analyte detection.  We have developed novel nanosensors, including an Ion-Selective Quantum Dot (ISQD) and a Chem-7 “tattoo”.  We are currently expanding our range of sensors into other areas, including neurotransmitters and other small molecules.  For every application, we are dedicated to applying our sensors to real problems in biology and medicine.  We have built strong collaborations with local, national, and international investigators in order to bring a team approach to these projects.