Sensitive determination of Norfloxacin in milk based on β-cyclodextrin functionalized silver nanoparticles SERS substrate

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2022-08, Vol.276, p.121212, Article 121212
• Main Authors: Qiu, Xiaoqian, Gu, Jiao, Yang, Taiqun, Ma, Chaoqun, Li, Lei, Wu, Yamin, Zhu, Chun, Gao, Hui, Yang, Zichen, Wang, Zirui, Li, Xiaolin, Hu, Anqi, Xu, Jinzeng, Zhong, Lvyuan, Shen, Jialu, Huang, Anlan, Chen, Guoqing
• Format: Article
• Language: English
• Subjects: Milk; Norfloxacin; Silver nanoparticles; Surface Enhanced Raman Spectroscopy; β-cyclodextrin
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2022.121212

[Display omitted] •The β-CD-AgNPs substrate can selectively combine with NFX. And the proposed method can be applied in the detection of real milk samples.•The “host–guest” interaction of NFX and β-CD-AgNPs was verified by the UV–Vis absorption spectroscopy, fluorescence spectroscopy, Zeta potential and DLS.•This developed SERS method is simple and sensitive, the LOD of NFX was 3.214 pmol/L in standard solution and 5.327 nmol/L in milk. The norfloxacin (NFX) residue in milk will increase human resistance to drugs and pose a threat to public health. In this work, a highly sensitive method for detection of NFX was developed based on surface enhanced Raman spectroscopy (SERS) using β-cyclodextrin functionalized silver nanoparticles (β-CD-AgNPs) as substrate. The unique spatial size and hydrophilicity of β-CD on the surface of AgNPs could selectively capture the target molecule (NFX) through some weak interactions, including hydrogen-bond interaction, electrostatic interaction, etc. The interactions were characterized by the UV–Vis absorption spectroscopy, fluorescence spectroscopy, Zeta potential and DLS. The Raman signal of NFX is largely enhanced when anchored by β-CD on the surface of AgNPs due to SERS effect. Through a series of experiments and analysis, the limit of detection (LOD) in standard solution and spiked milk were calculated to be 3.214 pmol/L and 5.327 nmol/L. The correlation coefficients (R2) were 0.986 and 0.984, respectively. For milk sample determination of NFX, the recovery was 101.29% to 104.00% with the relative standard deviation (RSD) from 2.986% to 9.136%. To sum up, this developed SERS strategy is sensitive and specific to detect NFX in milk, it has practical application value and prospects.