Characterization of proton transport across a waveguide-supported lipid bilayer.
Cellular energy transduction processes are often driven by transmembrane ion gradients, and numerous artificial biomembrane systems have been developed that allow for chemically or light-induced charge transport into/out of liposomes. Liposomal architectures, however, are not readily interfaced to a solid-state transducer. Formation of an ion gradient across a planar-supported membrane, "wired" to a substrate electrode, may ultimately allow utilization of the potential energy to drive other electrochemical processes. Described here is a novel conductive polymer/planar waveguide assembly that provides for highly sensitive transduction of proton transport across a planar-supported lipid bilayer (PSLB). A quinone proton shuttle is embedded in the PSLB, which is coupled to the planar optical waveguide electrode through a pH-sensitive, self-assembled conductive polymer film. Interfacial potential and absorbance changes in the conductive polymer film provide for sensitive characterization of transmembrane proton transport. The general and flexible nature of this architecture makes it adaptable to many different types of transmembrane transport chemistries, particularly light-activated systems.
McBee
Todd W
TW
Department of Chemistry, University of Arizona, Tucson, AZ 85721-0041, USA.
Wang
Liying
L
Ge
Chenhao
C
Beam
Brooke M
BM
Moore
Ana L
AL
Gust
Devens
D
Moore
Thomas A
TA
Armstrong
Neal R
NR
Saavedra
S Scott
SS
D000180:Acrylic Resins / Q000737:chemistry; D000814:Aniline Compounds / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D016227:Benzoquinones / Q000737:chemistry; D004566:Electrodes; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D011522:Protons; D013053:Spectrophotometry / Q000379:methods; D017971:Tin Compounds / Q000737:chemistry
D000180:Acrylic Resins; D000814:Aniline Compounds; D016227:Benzoquinones; D008051:Lipid Bilayers; D011522:Protons; D017971:Tin Compounds; C416807:polyaniline; C006903:carbopol 940; C109984:indium tin oxide; D001205:Ascorbic Acid