2. Academic Validation
  3. 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

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

  • Sensors (Basel). 2018 Dec 18;18(12):4493. doi: 10.3390/s18124493.
Hsueh-Hsia Wu 1,  Xin-Quan Liao 2,  Xin-Ying Wu 3,  Cheng-De Lin 4,  Kai-Ru Jheng 5,  Hong-Ren Chen 6,  Yong-Yi Wang 7,  Hsiu-Mei Chen 8
Affiliations

Affiliations

  • 1 School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan. wuhh@tmu.edu.tw.
  • 2 Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan. letter605@hotmail.com.
  • 3 Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan. ex8527@livemail.tw.
  • 4 Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan. gn01657736@hotmail.com.
  • 5 Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan. D9906104@mail.ntust.edu.tw.
  • 6 Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan. kenneth991020@gmail.com.
  • 7 Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan. Bright4522@yahoo.com.tw.
  • 8 Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan. hsiumei@mail.ntust.edu.tw.
PMID: 30567418 DOI: 10.3390/s18124493
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.

Keywords

bacteriorhodopsin; graphene oxide; monolayer fabrication; photoelectric immunosensor; protein A; purple membrane; shear flow.

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