Penn Collaboration Uses New Type of Graphene Sensor to Answer a Fundamental Nanotechnology Question

Physicists at the University of Pennsylvania have invented a new type of graphene-based sensor that could one day be used as a low-cost diagnostic system able to test for biomarker molecules, which are indicative of disease states. In collaboration with Penn chemists, the researchers published a paper in Chemical Science in which they use this sensor, for the first time, to directly answer a basic scientific question in nanotechnology about whether a particular protein maintains its structure when it assembles around an inorganic nanoparticle. The finding may have medical applications down the line. The research was led by Jinglei Ping, a postdoctoral researcher in the Department of Physics & Astronomy in Penn's School of Arts & Sciences , physics professor  A.T. Charlie Johnson and Katherine Pulsipher, now a postdoc in the Department of Chemistry. Chemistry professors Ivan Dmochowski and Jeffery Saven , graduate students Ramya Vishnubhotla and Jose Villegas and alumnae Tacey Hicks and Stephanie Honig also contributed to the study. This unique sensor, which the researchers call a graphene micro electrode, works by measuring the current that flows from a liquid sample to the graphene surface. The researchers found that this technique is especially useful in more complicated liquid samples, such as biological fluids, which typically have a lot of salt and proteins.