A filter paper coated with phenylboronic acid-modified mesoporous silica for enrichment of intracellular nucleosides prior to their quantitation by HPLC

The authors describe a filter paper modified with mesoporous silica that carries phenylboronic acid on its surface. The material possesses the advantages of the flexibility of filter paper and the large surface of mesoporous silica. This makes it an excellent sorbent for the enrichment of trace quantities of nucleosides. The limits of detection (in HPLC analysis with UV detection) are 2.0-11.1 mu g L-1 and the limits of quantification are 6.8-37.1 mu g L-1 with good precision (RSD < 6.4%). Compared to plain filter paper and nonporous silica-coated filter paper, the material exhibits enhanced efficiency and a 4.5-fold improved capacity. The potential applications are demonstrated by preconcentrating nucleosides from HepG2 cells which are a representative complex sample. The method was also used to study the effect of 30-nm gold nanoparticle on cellular metabolism.