Synthesis of fluorescent nanoparticle sensors for simultaneous determination of double targets

New fluorescent silica nanoparticles for sensors simultaneous determination of double targets were synthesized via a reverse microemulsion method based on the fluorescence resonance energy transfer (FRET). Nanoparticle A was doped with a dye complex which consisted of two dye molecules, fluorescein and tetram-ethylrhodamine. These dye molecules were first linked with avidin and biotin, respectively. They then formed a stable dye complex through avidin-biotin bridge within the distance of FRET. Nanoparticle B was doped with fluorescein only. As a result of this combination, the nanoparticles emit double wavelengths when a single excitation wavelength is used. The results show that the fluorescent nanoparticles are promising fluorescent labeling reagents for the sensitive detection of double targets.