Gold-Silver Core-Shell Nanoparticle Crosslinking Mediated by Protease Activity for Colorimetric Enzyme Detection.
Langmuir
; 38(46): 14200-14207, 2022 11 22.
Article
em En
| MEDLINE
| ID: mdl-36351199
ABSTRACT
Plasmonic nanoparticles produce a localized surface plasmon resonance (LSPR) under optical excitation. The LSPR of nanoparticles can shift in response to changes in the local dielectric environment and produce a color change. This color change can be observed by the naked eye due to the exceptionally large extinction coefficients (108-1011 M-1 cm-1) of plasmonic nanoparticles. Herein, we investigate the optical shifts (i.e., color change) of three unique gold-silver core-shell nanoparticle structures in response to changes in their dielectric environment upon nanoparticle aggregation. Aggregation is induced by a cysteine-containing peptide that has a sulfhydryl near its N and C termini, which crosslinks nanoparticles. Furthermore, we demonstrate that adding proline spacers between the cysteines impacts the degree of aggregation and, ultimately, the color response. Using this information, we construct a colorimetric enzyme assay, where the signal produced from nanoparticle aggregation is modulated by proteolysis. The degree of aggregation and the resulting optical shift can be correlated with enzyme concentration with high linearity (R2 = 0.998). Overall, this study explores the optical properties of gold-silver core-shell nanoparticles in a dispersed vs aggregated state and leverages that information to develop an enzyme sensor with a spectral LOD of 0.47 ± 0.09 nM.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nanopartículas Metálicas
/
Ouro
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
Langmuir
Assunto da revista:
QUIMICA
Ano de publicação:
2022
Tipo de documento:
Article