(472f) Graphene Paper Biosensor for Protein Detection

Sensor technology is evolving with the development of smaller devices with extremely sensitive detecting platforms.  These sensors have the potential to detect proteins and pathogens leading to a quick and inexpensive diagnose of diseases and biological responses in vivo and in vitro.  Carbon has recently been shown to be a sensitive platform for protein adsorption, therefore, we are working towards the creation of a carbon-based biosensor for protein detection.  Carbon nanotubes (CNTs) and graphene have been shown to detect protein adsorption due to the disruption of the electron-carrying crystalline network.  However, CNTs are costly and have a low yield.  Graphene nanoplatelets are difficult to work with due to their small size when it comes to the construction of medical devices.  We have chosen to use graphene/cellulose paper as our sensing platform.  Graphene paper is a novel technology and it has not been previously used as a carbon-based biosensor.  Graphene paper is inexpensive and available on a macroscale, making device construction simple.  The additives to the paper can be manipulated to increase the sensitivity and decrease the undesired absorption of proteins.  We have created a biosensor that detects proteins in solution by measuring the surface resistivity of graphene paper as a function of protein concentration.  Using the Langmuir isotherm model, we have determined that the dissociation constant is likely a function of the size of the protein.  This implies that hydrophobic interaction is the most likely cause of protein adsorption to the graphene paper.  The graphene paper has great potential for modification in order to create a specific protein detection device.