RESUMO
To add to the understanding of the properties of functionalized carbon nanotubes in biological applications, we report a monotonic pH sensitivity of the intracellular fluorescence emission of single-walled carbon nanotube-fluorescein carbazide (SWCNT-FC) conjugates in human ovarian cancer cells. Light-stimulated intracellular hydrolysis of the amide linkage and localized intracellular pH changes are proposed as mechanisms. SWCNT-FC conjugates may serve as intracellular pH sensors.
Assuntos
Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Espaço Intracelular/metabolismo , Microscopia de Fluorescência/métodos , Nanotubos de Carbono/química , Neoplasias Ovarianas/química , Linhagem Celular Tumoral , Feminino , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Microscopia Eletrônica de Varredura , Neoplasias Ovarianas/metabolismo , Análise Espectral RamanRESUMO
We report complementary detection of prostate-specific antigen (PSA) using n-type In2O3 nanowires and p-type carbon nanotubes. Our innovation involves developing an approach to covalently attach antibodies to In2O3 NW surfaces via the onsite surface synthesis of phosphonic acid-succinylimide ester. Electronic measurements under dry conditions revealed complementary response for In2O3 NW and SWNT devices after the binding of PSA. Real-time detection in solution has also been demonstrated for PSA down to 5 ng/mL, a benchmark concentration significant for clinical diagnosis of prostate cancer, which is the most frequently diagnosed cancer.