Sensing capabilities of colloidal gold monolayer modified with a phenylboronic acid-carrying polymer brush.
A dithiolated random copolymer with pendent phenylboronic acid residues [Cys-poly(3-acrylamidophenylboronic acid-co-N,N-dimethylaminopropyl methacrylamide), Cys-poly(APBA-co-DMAPMA)] that shows the abilities of initiation, transfer, and termination (iniferter) was obtained by using a benzyl N,N-diethyldithiocarbamoyl (BDC) derivative. The obtained disulfide-carrying copolymer was accumulated on a colloidal gold-immobilized glass substrate, and the usefulness of the polymer brush as a sensing element for glycoproteins such as ovalbumin (OVA) was examined by UV-visible spectrophotometry with the help of localized surface plasmon resonance (LSPR). The sensor showed a concentration-dependent binding of OVA with a detection limit of 100 nM, and it had a very high stability at high ionic strength. The sensor chip could be used for a detection of another glycoprotein, avidin, as well. Furthermore, the binding of biotin-modified human serum albumin (biotinylated HSA) to the avidin-phenylboronic acid- (PBA-) carrying polymer brush complex and further specific binding of anti-HSA immunoglobulin G to the biotinylated HSA-avidin-PBA-carrying polymer brush ternary complex could clearly be observed. The polymer-brush-coated device examined here not only was useful as a simple sensor chip, but also is expected to open a new perspective on interfacial phenomena performed by various functional polymer brushes fixed to colloidal gold on glass substrates.
Kitano
Hiromi
H
Department of Chemical and Biochemical Engineering, University of Toyama, Toyama, 930-8555 Japan. kitano@eng.u-toyama.ac.jp
Anraku
Yasutaka
Y
Shinohara
Hiroaki
H
D001897:Boronic Acids / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003102:Colloids / Q000737:chemistry*; D005898:Glass / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D008958:Models, Molecular; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D013499:Surface Properties; D013997:Time Factors
D001897:Boronic Acids; D003102:Colloids; D008567:Membranes, Artificial; D011108:Polymers; D006046:Gold; C010686:benzeneboronic acid