Synthesis and characterization of photoswitchable fluorescent silica nanoparticles.
We have designed and synthesized a new functional (amino reactive) highly efficient fluorescent molecular switch (FMS) with a photochromic diarylethene and a rhodamine fluorescent dye. The reactive group in this FMS -N-hydroxysuccinimide ester- allows selective labeling of amino containing molecules or other materials. In ethanolic solutions, the compound displays a large fluorescent quantum yield of 52 % and a large fluorescence modulation ratio (94 %) between two states that may be interconverted with red and near-UV light. Silica nanoparticles incorporating the new FMS were prepared and characterized, and their spectroscopic and switching properties were also studied. The dye retained its properties after the incorporation into the silica, thereby allowing light-induced reversible high modulation of the fluorescence signal of a single particle for up to 60 cycles, before undergoing irreversible photobleaching. Some applications of these particles in fluorescence microscopy are also demonstrated. In particular, subdiffraction images of nanoparticles were obtained, in the focal plane of a confocal microscope.
Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
Jonas
J
Fölling
Svetlana
S
Polyakova
Vladimir
V
Belov
Alfons
A
van Blaaderen
Mariano L
ML
Bossi
Stefan W
SW
Hell
D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010777:Photochemistry; D012822:Silicon Dioxide / Q000138:chemical synthesis* / Q000737:chemistry
D005456:Fluorescent Dyes; D012822:Silicon Dioxide