A functional protein of bacteriorhodopsin has been employed for an approach to develop molecular single-electron transistors. A purple-membrane nanofragment shows a characteristic, cyclic, and reproducible I-V curve having negative differential resistance and an on-off peak-to-valley ratio of 660. The conductance increases exponentially with temperature increase with an activation energy of 47 meV, comparable to the charging energy of a bacteriorhodopsin molecule. This with observed I-V scaling relationship indicates that the Coulomb blockade is the primary conductance-limiting feature and that charges are carried by arrayed Coulomb islands of bacteriorhodopsin.
Bibliographical noteFunding Information:
This work was supported by the Nano R&D (Grant No. M10703000871–07M0300–87110) and SRC (Grant No. R11–2007–012–01002–0) Programs of the Korea Science and Engineering Foundation. J.-Y.K. acknowledges the BK21 Scholarship as well.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)