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A novel methanofullerene containing pyridine pendants has been synthesized and used to fabricate a silver selective electrode. The selectivity coefficient was found to be 6.9 ×10-5 and 6.2 × 10-5, respectively, for Cu2+ and Hg2+, while for other cations it was less than 10-5. It has a Nernstian behavior over a wide concentration range of Ag+ ion (5 × 10-7 to 1 × 10-1 mol L-1). The slope and linear range from the calibration graph was found to be 58.8 mV decade-1 and 5.0 × 10-7 to 1.0 × 10-1 mol L-1, respectively. The limit of detection was found to be 1 × 10-7 mol L-1. The fabricated electrodes can be used in a wide pH range (pH 4-7.5) with a response time less than 10 s. The fabricated electrodes were used for bioanalysis of glucose with silver nanoparticle as the potential redox marker. The working linear range for glucose detection was found to be 1 × 10-5 to 1 × 10-3 in phosphate buffer (pH 6.6). Parameters affecting the reaction rate such as pH and the amount of GOx and AgNPs were analyzed. The lower detection limit was 1.0 × 10-6 M. The sensors exhibited very good repeatability with %R.S.D. < 6 and high sensor-to-sensor reproducibility. Application in analysis of glucose in real life sample (blood plasma) has also been demonstrated. [ABSTRACT FROM AUTHOR]

Two novel pyrazolino [60] fullerenes 2a - 2b have been prepared by 1, 3 dipolar cycloaddition reaction of nitrile imines, generated in situ from hydrazones 1a - 1b, to C60. All the synthesized compounds were characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR and mass spectral analysis. Charge-transfer interactions in the ground state between the indole ring and the fullerene cage has been monitored by photophysical and electrochemical studies. Electrochemical properties of the new dyads 2a-b showed better electron affinity with respect to C60. Steady state absorption and emission spectra studied as a function of dielectric constant of the medium, showed efficient electron transfer from indole to fullerene moiety in polar solvents such as CH2Cl2. Fluorescence lifetimes of the dyads 2a and 2b studied by nanosecond flash photolysis showed faster fluorescence decay of the dyads as compared by reference compound N-Methylpyrrolidino[60]fullerene. [ABSTRACT FROM AUTHOR]

A novel C2 symmetrical fullero-bis(pyrrolidine) dibenzo[18]crown-6 conjugate 3 with trans-1 addition pattern on the fullerene sphere has been prepared and characterised by elemental analysis, 1H NMR, 13C NMR and FAB-MS. NMR spectra are consistent with the isolation of a single regioisomer, assigned to the trans-1 bis-adduct of C60. Preliminary coordination studies by fluorimetry and UV-vis spectroscopy revealed that on inclusion of K+ in the crown ether cavity, cyclophane structured receptor 3 showed good selectivity in complexation towards [image omitted] as compared to other anions via favourable electrostatic effects. Cyclic voltammetric studies demonstrate that the presence of K+ amplifies the electrochemical response of 3 towards [image omitted] as compared to other anions. These results were corroborated by 1H NMR titration study which confirmed the binding site for both [image omitted] and K+ in the receptor. [ABSTRACT FROM AUTHOR]

Abstract: A novel water-soluble [60] fullerene-substituted lysine derivative 3 has been synthesized and characterized by elemental analysis, 1H NMR, 13C NMR and FAB-MS. The synthetic procedure involved condensation of Boc-protected lysine with terephthaldehyde followed by 1,3-dipolar cycloaddition reaction with C60 in the presence of sarcosine and finally deprotection of the amino group using trifluoroacetic acid. The synthesized compound 3 exhibited high DNA cleavage efficiency upon visible light irradiation in the presence of NADH. [Copyright &y& Elsevier]

Abstract: A series of novel fullerene derivatives bearing s-triazine moiety have been synthesized by adopting 1,3 dipolar cycloaddition reaction of C60 and azomethine ylides generated from the corresponding Schiff bases of 2,4,6 trisubstituted s-triazine. All the compounds synthesized were characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR and FAB-MS. The compounds were then screened for their antibacterial activity against both gram-positive (Staphylococcus aureus, Bacillus subtilis, Bacillus pumilis) and gram-negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) bacteria by disc diffusion method. All the compounds were found to be active against these strains at very low concentration and were comparable to standard drug ciprofloxacin. [Copyright &y& Elsevier]