Mono-6-Deoxy-6-Aminopropylamino-beta-Cyclodextrin on Ag-Embedded SiO2 Nanoparticle as a Selectively Capturing Ligand to Flavonoids

It has been increasingly important to develop a highly sensitive and selective technique that is easy to handle in detecting levels of beneficial or hazardous analytes in trace quantity. In this study, mono-6-deoxy-6-aminopropylamino-beta-cyclodextrin (pr-beta-CD)-functionalized silver-assembled silica nanoparticles (SiO2@Ag@pr-beta-CD) for flavonoid detection were successfully prepared. The presence of pr-beta-CD on the surface of SiO2@Ag enhanced the selectivity in capturing quercetin and myricetin among other similar materials (naringenin and apigenin). In addition, SiO2@Ag@pr-beta-CD was able to detect quercetin corresponding to a limit of detection (LOD) as low as 0.55 ppm. The relationship between the Raman intensity of SiO2@Ag@pr-beta-CD and the logarithm of the Que concentration obeyed linearity in the range 3.4-33.8 ppm (R-2 = 0.997). The results indicate that SiO2@Ag@pr-beta-CD is a promising material for immediately analyzing samples that demand high sensitivity and selectivity of detection.