RESUMO
Early detection of cancer often requires time consuming protocols and expensive instrumentation. To address these limitations, a Rose Bengal conjugated gold nanorod (RB-GNR) platform is developed for optical detection of cancer cells. The GNRs are modified by poly(allylamine hydrochloride) and conjugated with RB molecules to produce RB-GNRs which exhibit strong optical absorption in the near-infrared (NIR) region, good stability in aqueous solution, low cytotoxicity, and high specificity to oral cancer cells. The label-free sensing assay utilizes RB-GNRs as the sensing probe and by monitoring the aggregation-induced red-shift in the NIR absorption wavelength, specific and quantitative analysis of the oral cancer cell lysate is accomplished down to a detection limit of 2000 cells/mL. By employing the RB-GNRs as an imaging probe, an imaging assay is established on a home-made NIR absorption imaging system. Based on the NIR absorption by the RB-GNRs specifically conjugated with the oral cancer cells, multi-channel, rapid and quantitative detection of oral cancer cells is demonstrated. The high sensitivity and specificity of the RB-GNR platform as demonstrated by the two complementary assays provide non-invasive optical diagnostics of oral cancer cells enabling convenient screening and monitoring.
Assuntos
Diagnóstico por Imagem/métodos , Ouro , Neoplasias Bucais/diagnóstico , Nanotubos/química , Imagem Óptica/métodos , Rosa Bengala , Linhagem Celular Tumoral , Feminino , Humanos , Hidrodinâmica , Lactente , Masculino , Nanotubos/ultraestrutura , Poliaminas , Rosa Bengala/química , Sensibilidade e Especificidade , Espectroscopia de Luz Próxima ao Infravermelho , Eletricidade Estática , Ressonância de Plasmônio de Superfície , TemperaturaRESUMO
A new class of ratiometric fluorescence sensors composed of rare-earth (RE) compound nanotubes is described. Polyethylenimine-coated yttrium hydroxide fluoride nanotubes (YHF NTs) that were synthesized hydrothermally exhibit highly efficient fluorescence when doped with RE ions. The polyethylenimine on the NTs facilitates the incorporation of phosphors such as quantum dots or organic dyes onto the NT surface to produce dual-emitting nanocomposites which are excellent ratiometric fluorescence sensors. The phosphor layer and underlying tubes in the nanocomposites act as the indicator and reference probes, respectively. This ratiometric fluorescence method which can be applied to the detection of heavy metals in solutions, temperature sensing, and pH sensing boasts high sensitivity and selectivity as well as better accuracy than traditional intensity-based fluorescence methods.
