Microfluidic chip with thermoresponsive boronate affinity for the capture-release of cis-diol biomolecules.

The polydimethylsiloxane microfluidic chip grafted with poly(N-isopropylacrylamide-3-acrylamidephenylboronic acid) (P(NIPAAm-co-AAPBA)) was fabricated by UV-induced grafting polymerization for the capture-release of cis-diol-containing biomolecules by temperature-modulated changes instead of changing the pH value of the mobile phase. Based on the optimal time for benzophenone soaking and UV irradiation of grafting polymerization, P(NIPAAm-co-AAPBA) was successfully grafted on the polydimethylsiloxane substrates, which were characterized by scanning electron microscopy, water contact angle measurements, and Fourier transform infrared spectroscopy. The P(NIPAAm-co-AAPBA)-grafted polydimethylsiloxane microfluidic chip can be successfully used for the capture and release of cis-diol-containing adenosine by adjusting the temperature from 4 to 55°C, and the result was validated by Triple Quad liquid chromatography with mass spectrometry. With further development, the fabricated polydimethylsiloxane microfluidic chips might be chosen as a potential tool for the capture and release of cis-diol-containing macromolecules, such as horseradish peroxidase and glycoprotein.