SERS-Based Flavonoid Detection Using Ethylenediamine-β-Cyclodextrin as a Capturing Ligand
Jae Min Choi, Eunil Hahm, Kyeong Hui Park, Daham Jeong, Won‐Yeop Rho, Jaehi Kim, Dae Hong Jeong, Yoon‐Sik Lee, Sung Ho Jhang, Hyun Woo Chung, Eunae Cho, Jae‐Hyuk Yu, Bong‐Hyun Jun, Seunho Jung · Nanomaterials · 2017
Ethylenediamine-modified β-cyclodextrin (Et-β-CD) was immobilized on aggregated silver nanoparticle (NP)-embedded silica NPs (SiO2@Ag@Et-β-CD NPs) for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS) signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO2@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin. In particular, luteolin was detected more strongly in the linear range 10−7 to 10−3 M than various organic molecules, namely ethylene glycol, β-estradiol, isopropyl alcohol, naphthalene, and toluene. In addition, the SERS signal for luteolin captured by the SiO2@Ag@Et-β-CD NPs remained even after repeated washing. These results indicated that the SiO2@Ag@Et-β-CD NPs can be used as a rapid, sensitive, and selective sensor for flavonoids.