Biotin Binding Hardly Affects Electron Transport Efficiency across Streptavidin Solid-State Junctions

Sudipta Bera, Sharada Govinda, Jerry A. Fereiro, Israel Pecht, Mordechai Sheves, David Cahen

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


The electron transport (ETp) efficiency of solid-state protein-mediated junctions is highly influenced by the presence of electron-rich organic cofactors or transition metal ions. Hence, we chose to investigate an interesting cofactor-free non-redox protein, streptavidin (STV), which has unmatched strong binding affinity for an organic small-molecule ligand, biotin, which lacks any electron-rich features. We describe for the first time meso-scale ETp via electrical junctions of STV monolayers and focus on the question of whether the rate of ETp across both native and thiolated STV monolayers is influenced by ligand binding, a process that we show to cause some structural conformation changes in the STV monolayers. Au nanowire-electrode-protein monolayer-microelectrode junctions, fabricated by modifying an earlier procedure to improve the yields of usable junctions, were employed for ETp measurements. Our results on compactly integrated, dense, uniform, ∼3 nm thick STV monolayers indicate that, notwithstanding the slight structural changes in the STV monolayers upon biotin binding, there is no statistically significant conductance change between the free STV and that bound to biotin. The ETp temperature (T) dependence over the 80-300 K range is very small but with an unusual, slightly negative (metallic-like) dependence toward room temperature. Such dependence can be accounted for by the reversible structural shrinkage of the STV at temperatures below 160 K.

Original languageEnglish
Pages (from-to)1394-1403
Number of pages10
Issue number4
StatePublished - 31 Jan 2023
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2023 The Authors. Published by American Chemical Society.


D.C. and M.S. thank the Israel Science Foundation (ISF). M.S. thanks the Kimmelman Center for Biomolecular Structure and Assembly for partial support. The authors also thanks Dr. Sidney Cohen for useful advice and discussion regarding AFM, Dr. Thomas M. Brenner for Kelvin probe, Dr. Ayelet Vilan for useful scientific discussion, and Dr. Shailendra Kumar Saxena, Dr. Ishita Das, Dr. Pallavi Singh, and Sharon Garusi for technical support. M.S. holds the Katzir-Makineni Chair in Chemistry.

FundersFunder number
Israel Science Foundation


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