Local pH-responsive diazoketo-functionalized photoresist for multicomponent protein patterning.
Selective surface immobilization of multiple biomolecule components, under mild conditions where they do not denature, is attractive for applications in biosensors and biotechnology. Here, we report on a biocompatible and pH-responsive photoresist containing diazoketo-functionalized methacrylate, methacrylic acid, and poly(ethylene glycol) methacrylate monomers, where the photolithographic process may be carried out in a local pH range to minimize biomolecular denaturation. The polymer is insoluble or sparsely soluble in pH 6.4 or more acidic solution or deionized water, but soluble in a basic solution, pH 7.9 or more. After UV exposure, however, carboxylic acid groups are generated by Wolff rearrangement and photodissociation of the diazoketo groups in the polymer chain, leading to dissolution of UV-exposed polymer at pH 6.4. Using the property of the pH-solubility switching, we demonstrate dual streptavidin patterning using only biological buffers, pH 6.4 and 7.9 solutions, and double exposure patterning to confirm the sustainability of the diazoketo groups in unexposed regions despite carrying out several wet processes.
Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) , Yuseong-gu, Daejeon 305-701, Korea.
Je Moon
JM
Yun
Ramakrishnan
R
Ganesan
Jae-Hak
JH
Choi
Jin-Baek
JB
Kim
D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000138:chemical synthesis / Q000737:chemistry; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry; D012995:Solubility; D019809:Streptavidin / Q000737:chemistry* / Q000378:metabolism; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry
D008689:Methacrylates; C524499:polyethylene glycol methacrylate; D014867:Water; C008384:methacrylic acid; D011092:Polyethylene Glycols; D019809:Streptavidin