Sudhanshu P. Singh

Voltammetric determination of atenolol at C60-modified glassy carbon electrodes

C(60)-modified glassy carbon electrode has been found to exhibit excellent electrocatalytic activity towards atenolol oxidation for its voltammetric determination at physiological pH. Lowering of overpotential associated with atenolol oxidation indicates electrocatalytic nature of electrode. Determination of atenolol was carried out at pH 7.2 at modified electrode and a well-defined oxidation peak has been observed approximately 1040mV versus Ag/AgCl electrode for atenolol oxidation. Calibration plot having good co-linearity with a correlation coefficient 0.997 was obtained in the concentration range of 0.25-1.5mM atenolol and the sensitivity of the method has been found to be 8.58muAmM(-1). The detection limit is found to be 0.16mM. The method developed is applicable for atenolol determination in pharmaceutical preparations and urine samples. The modified electrode showed a good surface coverage ( approximately 85%) with C(60).

Synthesis of Nickel Hexacyanoferrate Nanoparticles and Their Potential as Heterogeneous Catalysts for the Solvent-Free Oxidation of Benzyl Alcohol

Abstract Nickel hexacyanoferrate nanoparticles were synthesized and characterized using elemental analysis, thermal analysis, infrared spectroscopy, and X-ray diffraction. A FE-SEM image of the nickel hexacyanoferrate showed that it consists of nearly spherical particles with sizes ranging from 30 to 70 nm. The synthesized material was found to be a heterogeneous catalyst useful for the solvent-free oxidation of benzyl alcohol with H 2 O 2 as an oxidant. A 36% conversion of benzyl alcohol to benzaldehyde was achieved under optimized reaction conditions using specific parameters such as the amount of catalyst, the temperature, the benzyl alcohol to H 2 O 2 molar ratio, and the reaction time.

Effect of graphite and metallic impurities of C60 fullerene on determination of salbutamol in biological fluids.

A new method for the determination of salbutamol has been developed using fullerene C60-modified glassy carbon electrode and validated using GC-MS. The presence of graphite and metallic impurities in C60 are found to diminish the peak. The oxidation of salbutamol was observed in a single well-defined, diffusion-controlled process using square wave voltammetry. The peak potential of oxidation peak was dependent on pH and determination was carried out at physiological pH 7.4. The peak current versus concentration plot was linear in the range 100-2000 ng/ml of salbutamol. The detection limit was found to be 40 ng/ml. The determination of salbutamol was carried out in human blood and urine samples and common interferents such as dopamine, ascorbic acid and uric acid do not interfere. The method proved to be specific, rapid, and accurate and can be easily applied for detecting cases of doping. A cross-validation of the observed results with GC-MS indicated a good agreement.

Fullerene C60 modified gold electrode and nanogold modified indium tin oxide electrode for prednisolone determination

The electrochemical determination of prednisolone has been investigated at fullerene-C(60)-modified gold (C(60)/Au) electrode and gold nanoparticles modified indium tin oxide (nano Au/ITO) electrode in phosphate buffer solution (PBS) of pH 7.2. During oxidation of prednisolone, an anodic peak with peak potential (E(p)) at 570 mV and 400 mV appeared at nano Au/ITO and C(60)/Au electrode, respectively. The experimental results revealed that gold nanoparticles as well as fullerene (C(60)) promote the rate of prednisolone oxidation by increasing the peak current (i(p)) and oxidizing at lower peak potentials as compared to the respective bare electrodes due to their electrocatalytic effect. The linear concentration range at both the electrodes was in the range of 1 microM to 0.10 mM. The detection limit obtained at C(60)/Au electrode was 26 nM, while at nano Au/ITO electrode the detection limit was 90 nM. The applicability of the method to direct assays of human urine and whole blood sample is described to use the method for testing cases of doping by athletes.

Voltammetric determination of anabolic steroid nandrolone at gold nanoparticles modified ITO electrode in biological fluids

The electrochemical behavior of nandrolone decanoate (ND) at gold nanoparticles modified indium tin oxide (ITO) electrode was investigated. Oxidation of ND has been carried out in phosphate containing supporting electrolyte in the pH range 2.1-9.2 and a well-defined oxidation peak was noticed. The peak potential (E(p)) of the oxidation peak decreases linearly with increasing pH. Linear calibration curve is obtained over the nandrolone decanoate concentration range of 50nM to 1.5muM at pH 7.2 with a detection limit of 1.36x10(-7)M. The proposed method is effectively applied to detect the concentration of ND in human blood serum and urine samples after 24 and 72h of intramuscular injection. The method is rapid and does not require any pre-treatment.