Label-free SERS detection of relevant bioanalytes on silver-coated carbon nanotubes: The case of cocaine.
Surface-enhanced Raman scattering (SERS) spectroscopy can be used for the label-free determination and quantification of relevant small biometabolites that are hard to identify by conventional immunological methods, in the absence of labelling. In this work, detection is based on monitoring the vibrational changes occurring at a specific biointerface (a monoclonal antibody, mAb) supported on silver-coated carbon nanotubes (CNT@Ag). Engineered CNT@Ag play a key role, as they offer a stable substrate to support the biointerface, with a high density of hot spots. Proof of concept is demonstrated through the analysis and quantification of the main cocaine metabolite benzoylecgonine. These results open a new avenue toward the generation of portable sensors for fast ultradetection and quantification of relevant metabolites. The use of discrete particles (CNT@Ag@mAb) rather than rough films, or other conventional SERS supports, will also enable a safe remote interrogation of highly toxic sources in environmental problems or in biological fluids.
Sanles-Sobrido
Marcos
M
Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain. macorrea@uvigo.es
Rodríguez-Lorenzo
Laura
L
Lorenzo-Abalde
Silvia
S
González-Fernández
Africa
A
Correa-Duarte
Miguel A
MA
Alvarez-Puebla
Ramón A
RA
Liz-Marzán
Luis M
LM
D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000378:metabolism; D003042:Cocaine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D008958:Models, Molecular; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
D000911:Antibodies, Monoclonal; D037742:Nanotubes, Carbon; D012834:Silver; C005618:benzoylecgonine; D003042:Cocaine