Biotin-containing phospholipid vesicle layer formed on self-assembled monolayer of a saccharide-terminated alkyl disulfide for surface plasmon resonance biosensing.
We describe a technique to form a biotin-containing phospholipid vesicle layer on a self-assembled monolayer (SAM) deposited on a gold surface to immobilize biotinylated receptor proteins for a surface plasmon resonance (SPR) biosensor. The adsorption of vesicle of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) was examined by SPR on the SAMs of dithiobis(1-deoxy-glucitol-1-carbamoyl pentane) (DDGP), 11-mercaptoundecanoic acid, 11-mercaptoundecanol, 11-amino-1-undecanethiol, and 12-mercaptododecane, and it was found that the DOPC vesicle rapidly adsorbed on the DDGP SAM to achieve the highest coverage of the surface. By quartz crystal microbalance with dissipation monitoring (QCM-D), the DOPC layer formed on the DDGP SAM was shown to be a vesicle layer, in which intact DOPC vesicles physisorbed on the SAM surface. To immobilize a biotinylated receptor protein, one of three biotinylated phospholipids, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(biotinyl) (biotin-DOPE), N-((6-(biotinoyl)amino)hexanoyl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (biotin-X-DHPE) and N-(biotinoyl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (biotin-DHPE), was mixed with DOPC to form a biotin-containing vesicle layer on the DDGP SAM. A comparative binding study of NeutrAvidin and the biotin-containing vesicle layers showed that the use of biotin-X-DHPE achieved the most rapid immobilization of NeutrAvidin on the vesicle layer at the highest surface density. Furthermore, biotinylated protein A, as a receptor protein, could be immobilized through NeutrAvidin on the vesicle layer containing DOPC and biotin-X-DHPE, and its reaction with immunoglobulin G, as an analyte, was successfully observed by SPR. The results demonstrate that the biotin-containing vesicle layer on the DDGP SAM must be a useful component for SPR biosensor surfaces.
OMRON-Endowed Chair in Nano Optical Devices, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan.
Yoshiko
Y
Ishizuka-Katsura
Tetsuichi
T
Wazawa
Tadato
T
Ban
Kenichi
K
Morigaki
Shigeru
S
Aoyama
D000478:Alkylation; D001360:Avidin / Q000032:analysis* / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004220:Disulfides / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
D004220:Disulfides; D008051:Lipid Bilayers; D010743:Phospholipids; D001360:Avidin; D001710:Biotin