SERS-Based Flavonoid Detection Using Ethylenediamine-β-Cyclodextrin as a Capturing Ligand

• Main Authors: Jae Min Choi, Eunil Hahm, Kyeonghui Park, Daham Jeong, Won-Yeop Rho, Jaehi Kim, Dae Hong Jeong, Yoon-Sik Lee, Sung Ho Jhang, Hyun Jong Chung, Eunae Cho, Jae-Hyuk Yu, Bong-Hyun Jun, Seunho Jung
• Format: Article
• Language: English
• Published: MDPI AG 2017-01-01
• Series: Nanomaterials
• Subjects: cyclodextrin; ethylenediamine cyclodextrin; surface-enhanced Raman scattering (SERS); flavonoids
• Online Access: http://www.mdpi.com/2079-4991/7/1/8

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.