RESUMO
Colloidal particles with fluorescence read-out are commonly used as sensors for the quantitative determination of ions. Calcium, for example, is a biologically highly relevant ion in signaling, and thus knowledge of its spatio-temporal distribution inside cells would offer important experimental data. However, the use of particle-based intracellular sensors for ion detection is not straightforward. Important associated problems involve delivery and intracellular location of particle-based fluorophores, crosstalk of the fluorescence read-out with pH, and spectral overlap of the emission spectra of different fluorophores. These potential problems are outlined and discussed here with selected experimental examples. Potential solutions are discussed and form a guideline for particle-based intracellular imaging of ions.
Assuntos
Técnicas Biossensoriais , Cálcio/química , Nanotecnologia/métodos , Óptica e Fotônica , Benzoxazinas/química , Endocitose , Corantes Fluorescentes/química , Ouro/química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Íons , Nanopartículas Metálicas/química , Microscopia de Fluorescência , Tamanho da Partícula , Peptídeos/química , Polímeros/químicaRESUMO
We have synthesized a series of four new promising D-π-A conjugated organic sensitizers with a proaromatic 4H-pyran-4-ylidene as a donor, a thiophene ring in the bridge, and 2-cyanoacrilic acid as acceptor. Comparison between different donor substituents and the modification of the thiophene ring resulted in molar extinction coefficients as high as 36399 M(-1) cm(-1) at 551 nm. The photovoltaic properties of the DSSCs demonstrate power conversion efficiencies as high as 5.4%.