Label-free selective SERS detection of PCB-77 based on DNA aptamer modified SiO₂@Au core/shell nanoparticles.
A label-free approach to selective detection of 3,3',4,4'-tetrachlorobiphenyl (PCB77) using aptamer modified silica-Au/core-shell nanoparticles (denoted as SiO2@Au core/shell NPs) through surface enhanced Raman scattering (SERS) spectroscopy was proposed. The devised system consisted of SiO2@Au core/shell NPs fixed on the amino-silane functionalized glass slides with the PCB77-binding aptamers attached covalently to the gold surfaces through a thiol linker. The aptamers made of single-stranded DNA (ssDNA) oligomers with one end standing on the Au surface changed the conformation upon conjugation with PCB77, which correspondingly caused the spectral response of the ssDNA oligomers. The intensity ratio I(660 cm(-1))/I(736 cm(-1)) decreased with the amount of PCB77 added, which thus allowed us to measure trace amounts of PCB77 in a selective and quantitative way. This work therefore demonstrates that the design of aptamer-modified SiO2@Au core/shell NPs can be utilized for label-free SERS detection of persistent organic pollutants (POPs) in the environment.
Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, PR China. huangq@ipp.ac.cn.
Yilin
Y
Lu
Qing
Q
Huang
Guowen
G
Meng
Lijun
L
Wu
Zhang
Z
Jingjing
D052157:Aptamers, Nucleotide; D001483:Base Sequence; D053758:Nanoparticles; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D012822:Silicon Dioxide / Q000737:chemistry*
D052157:Aptamers, Nucleotide; D012822:Silicon Dioxide; D011078:Polychlorinated Biphenyls; C028451:3,4,3',4'-tetrachlorobiphenyl