Camilla Schneier - University of Pennsylvania
Co-Author(s): Carl H. Naylor, Nicholas J. Kybert, Jin Xi, Gabriela Romero, Jeffery G. Saven, Renyu Liu, and A.T. Charlie Johnson, University of Pennsylvania, Philadelphia, PA
Monolayer molybdenum disulfide (MoS2) is a two-dimensional semiconductor with exciting properties including a tunable band gap, reasonable values of mobility and high on/off ratio. The monolayer aspect is here exploited for the development of highly sensitive and selective biosensors. Indeed, all the atoms on the surface are exposed to the environment and therefore are influenced by the reactions happening on its surface. MoS2 is first grown by chemical vapor deposition directly onto a silicon/silicon oxide wafers. Sulfur and Molybdenum are introduced into the furnace at 750C and after a 30min growth time monolayer MoS2 flakes will have grown across the chip. Pre-patterned devices on a silicon/silicon oxide wafer are made by traditional photolithography method. The MoS2 is then transferred by KOH method onto the devices creating arrays of monolayer MoS2 field effect transistors (FETs). These FETs are then functionalized and exposed to various concentrations of enkephalin, a protein associated with opioids. We demonstrate the growth of high quality monolayer single crystal MoS2 flakes. We then developed a scalable fabrication method for arrays of monolayer MoS2 FETs. We were able to measure the mobility, on/off ratio and threshold voltage of our devices. Finally we used the MoS2 FETs as a biosensor to detect low concentrations of enkephalin, using the MoS2 without enkephalin as our control. Future work involves expanding the biosensing aspect by incorporating other novel materials (such as tungsten disulfide), developing mechanisms to sense a wider variety of targets, and incorporated the system onto flexible substrate for every day usage.
Funder Acknowledgement(s): This work was funded by National Science Foundation (NSF) EFRI 2DARE program through Grant No. EFMA1542879. NSF Accelerating Innovation in Research program AIR ENG1312202. The Nano/Bio Interface Center NSF NSEC DMR0832802, FAER (Foundation for Anesthesia Education and Research, Principal Investigator, R.L.), NIH K08 (K08- GM-093115) (Principal Investigator, R.L.), NIH R01 1RO1GM111421, and GROFF (Principal Investigator, R.L.), and the Department of Anesthesiology and Critical Care at the University of Pennsylvania (Principal Investigator, R.L.).
Faculty Advisor: A.T.Charlie Johnson, firstname.lastname@example.org
Role: I helped grow the molybdenum disulfide as well as characterize it with atomic force microscopy. I also fabricated the devices using traditional photolithography methods. I also functionalized the molybdenum disulfide in order to attach the protein. Finally, I collected and analyzed current vs gate voltage data.