Rectified photocurrent in a protein based molecular photo-diode consisting of a cytochrome b562-green fluorescent protein chimera self-assembled monolayer

Biosens Bioelectron. 2004 May 15;19(10):1169-74. doi: 10.1016/j.bios.2003.11.016.

Abstract

We fabricated a self-assembled monolayer (SAM) of a chimeric protein created as a novel model protein for an artificial light-harvesting complex (LHC) composed of two proteins, cytochrome b(562) (cytb(562)) mutated for SAM fabrication (cytb(562), N22C, G82C) and enhanced green fluorescent protein (EGFP). The SAM formation of chimeric protein on a single-crystalline Au(111) substrate was confirmed by atomic force microscopy (AFM) measurement. The rectified photocurrent of the chimeric protein SAM on a gold substrate was detected by light-illumination scanning tunneling microscopy (LI-STM) co-operated with a lock-in technique. The photocurrent generation of the chimeric protein SAM was wavelength-specific to the light-illumination (488 nm), which indicated that the EGFP part of the chimera plays a role as a sensitizer in the photo-induced electron transfer process.

MeSH terms

  • Biosensing Techniques / instrumentation*
  • Cytochrome b Group*
  • Escherichia coli Proteins*
  • Models, Biological
  • Photosynthesis / physiology
  • Recombinant Fusion Proteins*
  • Spectrophotometry
  • Time Factors

Substances

  • Cytochrome b Group
  • Escherichia coli Proteins
  • Recombinant Fusion Proteins
  • cytochrome b562, E coli