Voltammetric Sensor Based on Nano TiO2 Powder Modified Glassy Carbon Electrode for Determination of Dopamine

Graphene and its nanocomposite material based electrochemical sensor platform for dopamine

In this review, the recent progress in the electrochemical sensing of dopamine with various graphene and their nanocomposite materials modified electrodes are presented.

Synthesis of Co/TiO2 Nanocomposite and its Use in Construction of a Sensitive and Selective Sensor for Determination of Ciprofloxacin

The Co/TiO2 nanocomposite was synthesized by a modified sol-gel method. The surface structure and composition of nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction analysis (XRD), Fourier transform infrared (FTIR) spectrometry, thermal gravimetric analysis (TGA) and N2 physisorption. A carbon paste electrode (CPE) modified with Co/TiO2 nanocomposite was prepared and used for low level determination of antibiotic ciprofloxacin (CF) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimized conditions, the modified electrode exhibited a linear response over the concentration range of 0.1 to 70 μM CF, with a detection limit of 0.03 μM. The proposed sensor was applied to the CF determination in serum and urine samples.

Synthesis of polyethylene glycol (PEG) assisted tungsten oxide (WO3) nanoparticles for L-dopa bio-sensing applications

Nanocrystalline tungsten oxides (WO(3-δ)) are currently receiving a lot of attention because of their interesting electrical, magnetic, optical and mechanical properties. In this report, we present the synthesis of PEG assisted tungsten oxide (WO(3)) nanoparticles by simple household microwave irradiation (2.45 GHz) method. The samples were characterized using powder X-ray diffraction (XRD), thermal analysis (TG/DTA), transmission electron microscopy (TEM), UV-visible diffusion reflectance spectroscopy (UV-VIS-DRS), cyclic voltammetry and electrochemical impedance spectroscopy. Powder XRD results revealed that both the samples prepared with and without surfactant crystallize in the orthorhombic structure corresponding to WO(3) · H(2)O phase. Subsequent annealing under identical conditions (600°C/air/6h) led to significantly different products i.e. monoclinic W(17)O(47) from surfactant free sample and orthorhombic WO(3) from PEG assisted sample. Blue emission was observed through UV-VIS-DRS with blue shift and the band gap energy was estimated as 2.7 and 3.28 eV for PEG assisted as prepared (WO(3) · H(2)O) and annealed samples (WO(3)) respectively. Electrochemical measurements have been performed on all the samples deposited on the surface of glassy carbon (GC) electrode which showed high sensitivity and good selectivity for PEG assisted sample (WO(3) · H(2)O) for the direct detection of L-dopa.