TY - JOUR
T1 - Magnetically Assisted Surface-Enhanced Raman Spectroscopy for the Detection of Staphylococcus aureus Based on Aptamer Recognition
AU - Wang, Junfeng
AU - Wu, Xuezhong
AU - Wang, Chongwen
AU - Shao, Ningsheng
AU - Dong, Peitao
AU - Xiao, Rui
AU - Wang, Shengqi
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/9/23
Y1 - 2015/9/23
N2 - A magnetically assisted surface-enhanced Raman scattering (SERS) biosensor for single-cell detection of S. aureus on the basis of aptamer recognition is reported for the first time. The biosensor consists of two basic elements including a SERS substrate (Ag-coated magnetic nanoparticles, AgMNPs) and a novel SERS tag (AuNR-DTNB@Ag-DTNB core-shell plasmonic NPs or DTNB-labeled inside-and-outside plasmonic NPs, DioPNPs). Uniform, monodisperse, and superparamagnetic AgMNPs with favorable SERS activity and magnetic responsiveness are synthesized by using polymer polyethylenimine. AgMNPs use magnetic enrichment instead of repeated centrifugation to prevent sample sedimentation. DioPNPs are designed and synthesized as a novel SERS tag. The Raman signal of DioPNPs is 10 times stronger than that of the commonly used SERS tag AuNR-DTNB because of the double-layer DTNB and the LSPR position adjustment to match the given laser excitation wavelength. Consequently, a strong SERS enhancement is achieved. Under the optimized aptamer density and linker length, capture by aptamer-modified AgMNPs can achieve favorable bacteria arrest (up to 75%). With the conventional Raman spectroscopy, the limit of detection (LOD) is 10 cells/mL for S. aureus detection, and a good linear relationship is also observed between the SERS intensity at Raman peak 1331 cm-1 and the logarithm of bacteria concentrations ranging from 101 to 105 cells/mL. With the help of the newly developed SERS mapping technique, single-cell detection of S. aureus is easily achieved.
AB - A magnetically assisted surface-enhanced Raman scattering (SERS) biosensor for single-cell detection of S. aureus on the basis of aptamer recognition is reported for the first time. The biosensor consists of two basic elements including a SERS substrate (Ag-coated magnetic nanoparticles, AgMNPs) and a novel SERS tag (AuNR-DTNB@Ag-DTNB core-shell plasmonic NPs or DTNB-labeled inside-and-outside plasmonic NPs, DioPNPs). Uniform, monodisperse, and superparamagnetic AgMNPs with favorable SERS activity and magnetic responsiveness are synthesized by using polymer polyethylenimine. AgMNPs use magnetic enrichment instead of repeated centrifugation to prevent sample sedimentation. DioPNPs are designed and synthesized as a novel SERS tag. The Raman signal of DioPNPs is 10 times stronger than that of the commonly used SERS tag AuNR-DTNB because of the double-layer DTNB and the LSPR position adjustment to match the given laser excitation wavelength. Consequently, a strong SERS enhancement is achieved. Under the optimized aptamer density and linker length, capture by aptamer-modified AgMNPs can achieve favorable bacteria arrest (up to 75%). With the conventional Raman spectroscopy, the limit of detection (LOD) is 10 cells/mL for S. aureus detection, and a good linear relationship is also observed between the SERS intensity at Raman peak 1331 cm-1 and the logarithm of bacteria concentrations ranging from 101 to 105 cells/mL. With the help of the newly developed SERS mapping technique, single-cell detection of S. aureus is easily achieved.
KW - Ag-coated magnetic nanoparticles
KW - Staphylococcus aureus
KW - aptamer
KW - single-cell detection
KW - surface-enhanced Raman spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84942287969&partnerID=8YFLogxK
U2 - 10.1021/acsami.5b06446
DO - 10.1021/acsami.5b06446
M3 - Article
C2 - 26322791
AN - SCOPUS:84942287969
SN - 1944-8244
VL - 7
SP - 20919
EP - 20929
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 37
ER -