Solid-State Protein Junctions: Cross-Laboratory Study Shows Preservation of Mechanism at Varying Electronic Coupling
Sabyasachi Mukhopadhyay,
Senthil Kumar Karuppannan,
Cunlan Guo,
Jerry A. Fereiro,
Adam Bergren,
Vineetha Mukundan,
Xinkai Qiu,
Olga E. Castañeda Ocampo,
Xiaoping Chen,
Ryan C. Chiechi,
Richard McCreery,
Israel Pecht,
Mordechai Sheves,
Rupali Reddy Pasula,
Sierin Lim,
Christian A. Nijhuis,
Ayelet Vilan,
David Cahen
Affiliations
Sabyasachi Mukhopadhyay
Weizmann Institute of Science, Rehovot 76100, Israel; Department of Physics, SRM University – AP, Amaravati, Andhra Pradesh 522502, India; Corresponding author
Senthil Kumar Karuppannan
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
Cunlan Guo
Weizmann Institute of Science, Rehovot 76100, Israel; Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China
Jerry A. Fereiro
Weizmann Institute of Science, Rehovot 76100, Israel
Adam Bergren
Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton AB T6G 2G2, Canada
Vineetha Mukundan
Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton AB T6G 2G2, Canada
Xinkai Qiu
Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
Olga E. Castañeda Ocampo
Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
Xiaoping Chen
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
Ryan C. Chiechi
Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
Richard McCreery
Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton AB T6G 2G2, Canada
Israel Pecht
Weizmann Institute of Science, Rehovot 76100, Israel
Mordechai Sheves
Weizmann Institute of Science, Rehovot 76100, Israel
Rupali Reddy Pasula
School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore
Sierin Lim
School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore
Christian A. Nijhuis
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore; Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore; Corresponding author
Ayelet Vilan
Weizmann Institute of Science, Rehovot 76100, Israel; Corresponding author
David Cahen
Weizmann Institute of Science, Rehovot 76100, Israel; Corresponding author
Summary: Successful integration of proteins in solid-state electronics requires contacting them in a non-invasive fashion, with a solid conducting surface for immobilization as one such contact. The contacts can affect and even dominate the measured electronic transport. Often substrates, substrate treatments, protein immobilization, and device geometries differ between laboratories. Thus the question arises how far results from different laboratories and platforms are comparable and how to distinguish genuine protein electronic transport properties from platform-induced ones. We report a systematic comparison of electronic transport measurements between different laboratories, using all commonly used large-area schemes to contact a set of three proteins of largely different types. Altogether we study eight different combinations of molecular junction configurations, designed so that Ageo of junctions varies from 105 to 10−3 μm2. Although for the same protein, measured with similar device geometry, results compare reasonably well, there are significant differences in current densities (an intensive variable) between different device geometries. Likely, these originate in the critical contact-protein coupling (∼contact resistance), in addition to the actual number of proteins involved, because the effective junction contact area depends on the nanometric roughness of the electrodes and at times, even the proteins may increase this roughness. On the positive side, our results show that understanding what controls the coupling can make the coupling a design knob. In terms of extensive variables, such as temperature, our comparison unanimously shows the transport to be independent of temperature for all studied configurations and proteins. Our study places coupling and lack of temperature activation as key aspects to be considered in both modeling and practice of protein electronic transport experiments.
