Fused-silica capillary (250 μm i.d. × 360 μm o.d.) was purchased from Yongnian Optic Fiber Plant (Hebei, China). Tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) were purchased from Wuhan University Silicone New Material (Wuhan, China). Azobisisobutyronitrile (AIBN) and poly(ethylene glycol) with the molecular weight of 6000 (PEG-6000) were all purchased from Shanghai Chemical Reagent Corporation (Shanghai, China). AIBN was purified by recrystallization from ethanol at 40°C. 3-acrylamidophenylboronic acid (AAPBA) and creatinine were purchased from Sigma-Aldrich (Beijing, China). Organic solvents were all of HPLC grade. The water used throughout all experiments was purified using a Milli-Q apparatus (Millipore, Bradford, USA). All other reagents were obtained from various commercial sources and were of analytical grade unless otherwise indicated.
2′-Deoxycytidine (dC), 2′-deoxyguanosine (dG), 2′-deoxyadenosine (dA), thymidine (T), cytidine (rC), guanosine (rG), adenosine (rA), uridine (rU), 1-methyladenosine, N6-methyladenosine, 5′-deoxyadenosine, inosine, xanthosine, 3-methylcytidine, N4-acetylcytidine, 5-methyluridine, 3-methyluridine, pseudouridine, double hydrogen zeatin-riboside (DHzR) were purchased from Sigma-Aldrich (Beijing, China). The standard solution of each analyte was prepared at 1.0 mg/mL in H2O and stored at −20°C.
2′-Deoxycytidine (dC), 2′-deoxyguanosine (dG), 2′-deoxyadenosine (dA), thymidine (T), cytidine (rC), guanosine (rG), adenosine (rA), uridine (rU), 1-methyladenosine, N6-methyladenosine, 5′-deoxyadenosine, inosine, xanthosine, 3-methylcytidine, N4-acetylcytidine, 5-methyluridine, 3-methyluridine, pseudouridine, double hydrogen zeatin-riboside (DHzR) were purchased from Sigma-Aldrich (Beijing, China). The standard solution of each analyte was prepared at 1.0 mg/mL in H2O and stored at −20°C.