Microchip-Grafted P(NIPAAm-co-VPBA) with Thermoresponsive Boronate Affinity for Capture–Release of cis-Diol Biomolecules

Based on the successful graft of P(N-isopropylacrylamide-4-vinylphenylboronic acid) [P(NIPAAm-co-VPBA)] on glass substrates by surface-initiated atom transfer radical polymerization, a microfludic chip with the performance of thermoresponsive boronate affinity was fabricated and was used for capture–release of the cis-diol biomolecule adenosine. The copolymers modified successfully on the surface of glass substrate were characterized by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. The results demonstrated that, by simply adjusting the temperature from 4 to 55 °C, the microchip grafted with P(NIPAAm-co-VPBA) was specific to the cis-diol-containing molecules, and can selectively and quickly realize the capture and release of the cis-diol biomolecule adenosine from the mixture of adenosine and deoxyadenosine, which was validated by high performance liquid chromatography/electronic spray ion–ion trap mass spectrometry (HPLC/ESI–ion trap MS). Moreover, less than 10 min was taken from injection to the collection of the sample at the end of the channel. With further development, the P(NIPAAm-co-VPBA)-grafted microchip with high selectivity and repeatability may be chosen as a promising tool for the enrichment of the cis-diol-containing biomolecules, such as glycoproteins, carbohydrates, glycosylated peptides, nucleosides, etc.