Enhancing the peroxidase-like activity and stability of gold nanoparticles by coating a partial iron phosphate shell.
Nanoscale
; 12(44): 22467-22472, 2020 Nov 28.
Article
em En
| MEDLINE
| ID: mdl-33150912
ABSTRACT
Using citrate-capped gold nanoparticles (AuNPs) as peroxidase-mimicking enzymes to design biosensors is hindered by their low catalytic activity and poor colloidal stability, resulting in limited sensitivity and large variations. Herein, the growth of a partial iron phosphate (FeP) shell with Fe2+ ions on citrate-capped AuNPs boosted the activity of the AuNPs by up to 20-fold. The FeP-enhanced activity was demonstrated on AuNPs of different sizes, and gold nanostars. When the FeP layer is thick enough to block the access to the Au/FeP interface, the activity was inhibited. Capping the remaining Au surface by thiol also inhibited the activity, suggesting that faster reactions occurred at the interfaces of Au/FeP. Moreover, a FeP shell can stabilize AuNPs against freezing and a high NaCl concentration of 1 M. Sensitive detection of Fe2+ was achieved with a detection limit of 0.41 µM, while no other tested transition metal phosphates enhanced the peroxidase-like activity of AuNPs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nanopartículas Metálicas
/
Ouro
Idioma:
En
Revista:
Nanoscale
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Canadá