Versatile protein-a coated photoelectric immunosensors with a purple-membrane monolayer transducer fabricated by affinity-immobilization on a graphene-oxide complexed linker and by shear flow

Hsueh Hsia Wu, Xin Quan Liao, Xin Ying Wu, Cheng De Lin, Kai Ru Jheng, Hong Ren Chen, Yong Yi Wang, Hsiu Mei Chen

Research output: Contribution to journalArticlepeer-review

Abstract

Bacteriorhodopsin-embedded purple membranes (PM) have been demonstrated to be a sensitive photoelectric transducer for microbial detection. To efficiently prepare versatile BR-based immunosensors with protein A as antibody captures, a large, high-coverage, and uniformly oriented PM monolayer was fabricated on an electrode as an effective foundation for protein A conjugation through bis-NHS esters, by first affinity-coating biotinylated PM on an aminated surface using a complex of oxidized avidin and graphene oxide as the planar linker and then washing the coating with a shear flow. Three different polyclonal antibodies, each against Escherichia coli, Lactobacillus acidophilus, and Streptococcus mutans, respectively, were individually, effectively and readily adsorbed on the protein A coated electrodes, leading to selective and sensitive quantitative detection of their respective target cells in a single step without any labeling. A single-cell detection limit was achieved for the former two cells. AFM, photocurrent, and Raman analyses all displayed each fabricated layer as well as the captured bacteria, with AFM particularly revealing the formation of a massive continuous PM monolayer on aminated mica. The facile cell-membrane monolayer fabrication and membrane surface conjugation techniques disclosed in this study may be widely applied to the preparation of different biomembrane-based biosensors.

Original languageEnglish
Article number4493
JournalSensors (Switzerland)
Volume18
Issue number12
DOIs
Publication statusPublished - Dec 1 2018

Keywords

  • Bacteriorhodopsin
  • Graphene oxide
  • Monolayer fabrication
  • Photoelectric immunosensor
  • Protein A
  • Purple membrane
  • Shear flow

ASJC Scopus subject areas

  • Analytical Chemistry
  • Atomic and Molecular Physics, and Optics
  • Biochemistry
  • Instrumentation
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Versatile protein-a coated photoelectric immunosensors with a purple-membrane monolayer transducer fabricated by affinity-immobilization on a graphene-oxide complexed linker and by shear flow'. Together they form a unique fingerprint.

Cite this