Ru(ii)–carbohydrate dendrimers as photoinduced electron transfer lectinbiosensors

Abstract

Three tris(bipyridine)ruthenium dendrimers bearing either six or eighteen mannose units have been synthesized; encapsulation of the Ru(bipy)3 core alters the rate of energy and electron transfer as well as the lectin biosensing abilities.

Fluorescence emission and polarization analyses for evaluating binding of ruthenium metalloglycoclusters to lectins and tetanus toxin C-fragment

“…Using [Ru(dmso) 4 Cl 2 ] (0.8 mg, 1.7 × 10 − 6 mol) and 3 equiv of bpy-2Glc (5.0 mg, 5.0 × 10 − 6 mol), Ru(bpy-2Glc) 3 …”

“…[Ru(bpy-2Gal) 3 ], [Ru(bpy-2Glc) 3 ], [Ru(bpy) 2 (bpy-2Gal)], and [Ru(bpy) 2 (bpy-2Glc)] were prepared by following the general synthetic procedure as shown in Fig. 1.…”

“…All spectra of the metalloglycoclusters were measured using 100 μM of the metalloglycocluster [Ru(bpy-2Gal or Glc) 3 Fluorescence polarization (FP), P, was calculated using the equation P = (I -I ⊥ × G)/(I + I ⊥ × G), where I is the fluorescence intensity using the polarizer at 0 deg for excitation (I and I ⊥ were observed using the emission polarization filter at 0 and 90 deg, respectively). The correction factor G was determined using the following equation…”

“…The 3 ] or [Ru(bpy) 2 (bpy-2Glc)] were determined using nonlinear least-squares fitting. Using the fluorescence polarization value, the data were fitted to the equation…”

“…[2][3][4][5] The use of metalloglycoclusters as a probe molecule is an attractive proposition because the metal center furnishes photochemical and electrochemical properties that can be employed as useful analytical indicators in kinetic studies. Gottschaldt et al 6 reported on metalloglycoclusters that contain a rhenium or technetium metal center, and Kobayashi et al 2 and Kikkeri et al 3 reported on ruthenium metalloglycoclusters. Because the clusters can possess a variety of coordination numbers, in addition to providing useful photochemical and electrochemical properties, unique geometrical features can be imparted to the carbohydrate probe.…”