Detecting Trace Melamine in Solution by SERS Using Ag Nanoparticle Coated Poly(styrene-co-acrylic acid) Nanospheres as Novel Active Substrates

作者：Li Ju Mei; Ma Wan Fu; Wei Chuan; You Li Jun; Guo Jia; Hu Jun; Wang Chang Chun^*

来源：Langmuir, 2011, 27(23): 14539-14544.

DOI：10.1021/la203049k

A systematic study for the preparation of Ag nanoparticle (Ag-NP) coated poly(styrene-co-acrylic acid) (PSA) composite nanospheres by in situ chemical reduction is reported. The experimental results showed that the reaction temperature and the surface coverage of the -COOH determined the surface coverage and grain size of Ag nanoparticles on the PSA nanospheres. The surface enhanced Raman spectroscopy (SERS) sensitivity was investigated using 4-hydroxythiophenol (4-HBT) as the model probe in the solution of composite nanospheres stabilized by polyvinylpyrrolidone (PSA/Ag-NPs/PVP), with the detection limit of about 1 x 10(-6) M. Potential application of the new SERS substrate was demonstrated with the detection of melamine, and the detection limit was about 1 x 10(-3) M. Chemical noises from PVP and other impurities were observed and attributed mainly to the competitive adsorption of PVP on the surfaces of Ag-NPs. After tetrahydrofuran washing of the PSA/Ag-NPs/PVP substrates that removed the PVP and other residuals, the signal/noise levels of SERS were greatly improved and the detection limit of melamine was determined to be 1 x 10(-7) M. This result indicated that the new PSA/Ag-NPs system is highly effective and can be used as the SERS-active Substrate for trace analysis of a variety of drugs and food additives.

• 出版日期2011-12-6
• 单位景德镇陶瓷大学; 复旦大学