A new type of pH-responsive hydrogel surface with varying nanoparticle adsorptivities was fabricated to form a micro-patterned film. To increase its responsivity to environmental pH changes, we incorporated graphene oxide (GO) into a poly(methacrylic acid)-polyethylene glycol copolymer. Incorporating GO in the pH-responsive hydrogel significantly increased the adsorption-desorption responsivity of Ag nanoparticles on the gel surface. A pH oscillator in a closed reaction system composed of BrO3--Fe(CN)64--SO32- facilitated the self-oscillating adsorption-desorption of Ag nanoparticles on the GO-incorporated gel surface. The reversible adsorption-desorption of Ag nanoparticles on the patterned hydrogel surface in response to pH oscillations was determined using UV-visible spectroscopy in aqueous solution. The observed heterogeneous oscillations indicated that the adsorptivity of the gel surface can be reversibly changed on the patterned pH-responsive gel. This phenomenon is similar to various natural biological systems.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry