PMID- 17187966
OWN - NLM
STAT- MEDLINE
DCOM- 20070419
LR  - 20091016
IS  - 0927-7765 (Print)
IS  - 0927-7765 (Linking)
VI  - 55
IP  - 1
DP  - 2007 Mar 15
TI  - Chemical force titrations of antigen- and antibody-modified 
      poly(methylmethacrylate).
PG  - 107-14
AB  - Poly(methylmethacrylate) (PMMA) is a versatile polymer that displays desirable 
      properties for development of cheap and disposable microfluidic devices for 
      sensing biomolecular interactions. Atomic force microscopy (AFM) and chemical 
      force titrations were used to determine the efficacy of surface modifications 
      made to accommodate protein-substrate linkage. AFM images show the effects on 
      surface morphology of carboxylated-, amine-, hCG antigen- and anti-hCG 
      antibody-modified PMMA substrates. Confocal microscopy was used to determine the 
      fluorescent intensity of labeled antibody species on the PMMA substrate, 
      confirming the success of surface antigen/antibody immobilization. Surface 
      pK(1/2) value for carboxylic acid and amine species grafted on PMMA were 
      determined. When carboxylic acid or amine-terminated tips were titrated against 
      PMMA samples terminated with the hCG antigen and anti-hCG antibody, peaks 
      appeared in the force titration curve consistent with the pI range of the antigen 
      or antibody species. Strong adhesive forces were present at pH values above 7.0 
      when the antigen was present on the PMMA substrate, and these were attributed to 
      hydrophobic interactions between the antigen and the alkane "linker" chain 
      attaching the amine or carboxylate group to the AFM tip. Such hydrophobic 
      interactions were not observed with the carboxylic acid or amine/antibody 
      combinations suggesting that the surface-linked antibody was more resistant to 
      denaturation under higher pH. The results demonstrated the feasibility of using 
      AFM approaches for interrogating protein grafting strategies in the fabrication 
      of PMMA-based microsystems.
FAU - Wang, Bin
AU  - Wang B
AD  - Cancer Research Institute, Botterell Hall, Queen's University, Kingston, Ontario, 
      Canada.
FAU - Oleschuk, Richard D
AU  - Oleschuk RD
FAU - Petkovich, P Martin
AU  - Petkovich PM
FAU - Horton, J Hugh
AU  - Horton JH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20061125
PL  - Netherlands
TA  - Colloids Surf B Biointerfaces
JT  - Colloids and surfaces. B, Biointerfaces
JID - 9315133
RN  - 0 (Antibodies)
RN  - 0 (Chorionic Gonadotropin)
RN  - 9011-14-7 (Polymethyl Methacrylate)
SB  - IM
MH  - Antibodies/*chemistry/immunology
MH  - Antigen-Antibody Reactions
MH  - Chorionic Gonadotropin/*chemistry/immunology
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Microscopy, Atomic Force
MH  - Particle Size
MH  - Polymethyl Methacrylate/*chemistry
MH  - Sensitivity and Specificity
MH  - Surface Properties
MH  - Titrimetry/instrumentation/methods
EDAT- 2006/12/26 09:00
MHDA- 2007/04/20 09:00
CRDT- 2006/12/26 09:00
PHST- 2006/07/04 00:00 [received]
PHST- 2006/11/21 00:00 [revised]
PHST- 2006/11/21 00:00 [accepted]
PHST- 2006/12/26 09:00 [pubmed]
PHST- 2007/04/20 09:00 [medline]
PHST- 2006/12/26 09:00 [entrez]
AID - S0927-7765(06)00394-8 [pii]
AID - 10.1016/j.colsurfb.2006.11.026 [doi]
PST - ppublish
SO  - Colloids Surf B Biointerfaces. 2007 Mar 15;55(1):107-14. doi: 
      10.1016/j.colsurfb.2006.11.026. Epub 2006 Nov 25.