The detection performance in solution and in live cells of a novel mono-boronic acid derivative of a near-infrared luminescent tricarbocyanine with OFF–ON response upon addition of saccharides.

The modulation of the fluorescence emission of a perylene dye between ON and OFF states was achieved with high efficiency by means of a diarylethene photochromic compound in an organogel medium. Fluorescent gels were prepared from a steroidal low molecular weight organogelator doped with the perylene fluorophore. The compatibility of the photochromic compound in this medium and the non-destructive readout capability were demonstrated. The dye doped organogel was further used as a template and an innovative method was employed to grow fluorescent silica spherical nanoparticles with physically and chemically admixed perylene dye.

We report the synthesis of a near-infrared (NIR) fluorescent pH probe with a remarkable Stokes shift (∼135 nm) based on a tricarbocyanine (Cy-PIP). The fluorescent molecule was anchored to SiO₂ nanoparticles (Cy-PIP@SiO₂) and is capable of monitoring pH changes within the physiological range (pH 6–8). The Cy-PIP@SiO₂ nanoparticles were successfully internalized by HeLa cells as shown by fluorescence confocal microscopy, while flow cytometry revealed pH fluctuations during the endocytic pathway.

We present a water soluble and fluorescent biotinylated probe derived from a carbocyanine dye. A high efficiency of energy transfer was measured when the dyes were placed on the surface of streptavidin conjugated quantum dots. The system is a model platform for potential application as a FRET-based fluorescent sensor.

In this review we present characterization and synthetic chemistry guidelines for obtaining COOH-based alkoxysilanes aiming at SiO₂ modification. Applications of these derivatized materials related to biology and medicine are also discussed.