Biocompatible and flexible graphene oxide/upconversion nanoparticle hybrid film for optical pH sensing.
Phys Chem Chem Phys
; 16(4): 1576-82, 2014 Jan 28.
Article
em En
| MEDLINE
| ID: mdl-24309538
ABSTRACT
Free-standing optical hybrid film which is composed of positively-charged polyethylenimine-coated NaYF4Yb,Er nanoparticles and negatively-charged graphene oxide (GO) has been developed to measure pH based on the pH-dependent luminescence quenching effect caused by GO. The isothermal titration calorimetry analyses indicate that the interaction between GO and NaYF4Yb,Er nanoparticles becomes stronger with increasing pH, leading to a more significant fluorescence quenching of NaYF4Yb,Er nanoparticles at high pH values. The excellent mechanical properties of the hybrid film endow the thin-film pH sensor with better repeatability and higher stability during the measurements. Quantitatively, the upconversion luminescence intensity of the hybrid film exhibits a linear trend over the pH range of 5.00-8.00. Because of excitation with a 980 nm laser, as expected, the hybrid film sensor is also sensitive to the urine measurements with reduced background absorption. In addition to its good biocompatibility, our free-standing hybrid film sensor would be a promising candidate for biological, medical, and pharmaceutical applications.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Óxidos
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Materiais Biocompatíveis
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Nanopartículas
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Grafite
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article