title: Influence of ancillary binding and nonspecific adsorption on bioresponsive hydrogel microlenses.
abstract: We report investigations of specific and nonspecific adsorption effects on bioresponsive hydrogel microlenses to better understand their utility and potential advantages for biosensing. Bioresponsive microgels were prepared from stimuli-responsive poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM-co-AAc) microgels after functionalization with both biotin and ABP (as a photoaffinity label) via carbodiimide chemistry. Bioresponsive hydrogel microlenses were then constructed from the microgels via Coulombic assembly of the anionic microgels on a positively charged, silane-modified, glass substrate. Specific and nonspecific protein binding on the hydrogel microlenses was studied by monitoring the optical properties using brightfield and fluorescence optical microscopies. The bioresponsivity, as determined by changes in the microlensing power, is strongly coupled to the formation of cross-links via ligand-protein and/or antigen-antibody binding. However, the microlensing phenomenon and the intrinsic bioresponsivity of the hydrogels are completely insensitive to simple adsorption via nonspecific protein binding from reconstituted human serum. These results suggest that the hydrogel microlens construct may be a good candidate for a wide range of applications in which the bioresponsive material would be required to operate in complex biological media.
authors: School of Chemistry and Biochemistry & Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
authors: Jongseong
authors: J
authors: Kim
authors: Neetu
authors: N
authors: Singh
authors: L Andrew
authors: LA
authors: Lyon
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry*; D001798:Blood Proteins / Q000737:chemistry; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D011485:Protein Binding; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D001798:Blood Proteins; D020100:Hydrogels