One-Pot Silver Nanoring Synthesis

Silver colloidal nanorings have been synthesized by reducing silver ions with NaBH4 in trisodium citrate buffers. pH increase, by addition of NaOH, was used to speed up reduction reaction. The UV–vis absorption spectra of resulting silver nanorings showed two peaks accounting for transverse and longitudinal surface plasmon resonance, at ≈400 nm, and between 600 and 700 nm, respectively. The shapes of these silver nanoparticles (nanorings) depended on AgNO3/NaBH4 ratio, pH and reaction temperature. Particles were analysed by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. A reaction pathway is proposed to explain silver nanoring formation

Design and synthesis of water-soluble polyaminated chlorins and bacteriochlorins - With near-infrared absorption

International audienc

High yield preparation of purpurin-18 from Spirulina maxima

International audiencePurpurin-18, a derivative of chlorophyll, is an interesting dihydroporphyrin for generating photosensitizers such as purpurinimides which absorb light in the 700-850 nm range and which display efficient anti-tumor activity. To promote extensive utilization of Pp-18 as a starting material for the preparation of new photosensitizers, a simple and rapid method for obtaining this chlorin in high yield from Spirulina maxima is described. Optimized experimental conditions were determined using a Latin square design of experiments

Optimization of the arsenazo-III method for the determination of uranium in water and plant samples

International audienc

Use of fonctionnalized gold nanoparticles to assay uranium

The subject of the invention is the use of particular functionalized gold nanoparticles to determine the presence and/or assay the amount of uranium in a solution. After the functionalized gold nanoparticles have been placed in the solution, the assay may especially be carried out by spectrophotometry. The invention also relates to a kit that can be used for uranium assays in situ in the field

Chlorin-PEI-labeled cellulose nanocrystals: synthesis, characterization and potential application in PDT.

International audienceThis Letter reports the synthesis and characterization of a new series of water-stable and soluble photosensitizers (PS-CNCs) composed of cellulose nanocrystals (CNCs) bearing polyaminated chlorin p6. With a view to improve cancer cell targeting, these photosensitizers were assayed for their antitumor activity against HaCat cell line. IC(50) values fell within the nanomolar-range, making these photosensitizers promising for further in vitro and in vivo investigations

Sensing of the uranyl ion based on its complexation with bisphosphonate-capped gold nanoparticles

International audienceWe describe a sensing system that relies upon the formation of specific complexes between uranyl ion and bisphosphonate-capped gold nanoparticles. The ensuing concentration-dependent red-shift of surface plasmon resonance absorption allows the determination of uranyl ion concentration within the 1.5-15 ppm range