TY - JOUR
T1 - Thiol-polyethylene glycol-folic acid (HS-PEG-FA) induced aggregation of Au@Ag nanoparticles
T2 - a SERS and extinction UV–Vis spectroscopy combined study
AU - Verdin, Alexandre
AU - Malherbe, Cedric
AU - Sloan-Dennison, Sian
AU - Faulds, Karen
AU - Graham, Duncan
AU - Eppe, Gauthier
PY - 2024/12/5
Y1 - 2024/12/5
N2 - Plasmonic colloidal nanoparticles (NPs) functionalised with polymers are widely employed in diverse applications, offering advantages demonstrated over non-functionalised NPs such as enhanced colloidal stability or increased biocompatibility. However, functionalisation with polymers does not always increase the stability of the colloidal system. This work explores the intricate relationship between the functionalisation of plasmonic core@shell Au@Ag nanoparticles (NPs) with thiol-polyethylene glycol-folic acid (HS-PEG-FA) polymer chains and the resulting stability and spectral characteristics of Surface-Enhanced Raman Scattering (SERS) nanotags based on these NPs. We demonstrate that varying levels of HS-PEG-FA grafting influence nanotag stability, with a low level of grafting causing aggregation and subsequently affecting the spectral signature of Raman-reporter molecules attached to the surface of the NP. Electrostatic destabilisation is identified as the primary mechanism driving aggregation, impacting the SERS spectrum of Malachite Green isothiocyanate (MGITC) whose spectral shape is different between the aggregated and non-aggregated NPs. The findings provide valuable insights into NPs stability under different conditions, offering essential considerations for the design and optimisation of SERS nanotags in bio-analytical applications, particularly those involving data processing based on spectral shape, such as in multiplex approaches where experimental spectra are decomposed with several reference components.
AB - Plasmonic colloidal nanoparticles (NPs) functionalised with polymers are widely employed in diverse applications, offering advantages demonstrated over non-functionalised NPs such as enhanced colloidal stability or increased biocompatibility. However, functionalisation with polymers does not always increase the stability of the colloidal system. This work explores the intricate relationship between the functionalisation of plasmonic core@shell Au@Ag nanoparticles (NPs) with thiol-polyethylene glycol-folic acid (HS-PEG-FA) polymer chains and the resulting stability and spectral characteristics of Surface-Enhanced Raman Scattering (SERS) nanotags based on these NPs. We demonstrate that varying levels of HS-PEG-FA grafting influence nanotag stability, with a low level of grafting causing aggregation and subsequently affecting the spectral signature of Raman-reporter molecules attached to the surface of the NP. Electrostatic destabilisation is identified as the primary mechanism driving aggregation, impacting the SERS spectrum of Malachite Green isothiocyanate (MGITC) whose spectral shape is different between the aggregated and non-aggregated NPs. The findings provide valuable insights into NPs stability under different conditions, offering essential considerations for the design and optimisation of SERS nanotags in bio-analytical applications, particularly those involving data processing based on spectral shape, such as in multiplex approaches where experimental spectra are decomposed with several reference components.
KW - aggregation
KW - colloids
KW - polyethylene glycol
KW - SERS
KW - stability
KW - UV–Vis extinction
UR - http://dx.doi.org/10.2139/ssrn.4803211
UR - https://doi.org/10.17868/strath.00090087
U2 - 10.1016/j.saa.2024.124848
DO - 10.1016/j.saa.2024.124848
M3 - Article
AN - SCOPUS:85199104818
SN - 1386-1425
VL - 322
JO - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
JF - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
M1 - 124848
ER -