Padmanathan Karthick Kannan

High Performance Non-enzymatic Glucose Sensor Based on One-Step Electrodeposited Nickel Sulfide.

Nanostructured NiS thin film was prepared by a one-step electrodeposition method and the structural, morphological characteristics of the as-prepared films were analyzed by X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The electrocatalytic activity of NiS thin film towards glucose oxidation was investigated by fabricating a non-enzymatic glucose sensor and the sensor performance was studied by cyclic voltammetry (CV) and amperometry. The fabricated sensor showed excellent sensitivity and low detection limit with values of 7.43 μA μM(-1)  cm(-2) and 0.32 μM, respectively, and a response time of <8 s.

Highly sensitive and selective electrochemical dopamine sensing properties of multilayer graphene nanobelts

In the present study, we report the electrochemical sensing property of multi-layer graphene nanobelts (GNBs) towards dopamine (DA). GNBs are synthesized from natural graphite and characterized by using techniques like field-emission scanning electron microscopy, atomic force microscopy and Raman spectroscopy. An electrochemical sensor based on GNBs is developed for the detection of DA. From the cyclic voltammetry and amperometry studies, it is found that GNBs possess excellent electrocatalytic activity towards DA molecules. The developed DA sensor showed a sensitivity value of 0.95 μA μM(-1) cm(-2) with a linear range of 2 μM to 0.2 mM. The interference data exhibited that GNB is highly selective to DA even in the presence of common interfering species like ascorbic acid, uric acid, glucose and lactic acid.

Electrochemical sensing of hydrazine using multilayer graphene nanobelts

The electrochemical sensing property of multi-layer graphene nanobelts (GNB) towards hydrazine is studied. The developed hydrazine sensor showed a sensitivity value of 0.08 μA μM−1 cm−2 with a linear range of 10 μM to 1.36 mM. The interference data also exhibited high selectivity to hydrazine even in the presence of common interfering species like ascorbic acid, uric acid, glucose and lactic acid.

One-Step Electrodeposition of NiCo2S4 Nanosheets on Patterned Platinum Electrodes for Non-Enzymatic Glucose Sensing

The preparation of NiCo2 S4 (NCS) nanosheets on photolithographically patterned platinum electrodes by electrodeposition was explored. The as-prepared nanosheets were systematically characterized by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy techniques. The NCS-modified Pt electrode was used as a non-enzymatic glucose sensor. The sensor response exhibited two linear regions in glucose concentration, with a limit of detection of 1.2 μm. The sensors showed that the as-prepared NCS nanosheets have excellent electrocatalytic activity towards glucose with long stability, good reproducibility, and excellent anti-interference properties, and thus, this material holds promise for the development of a practical glucose sensor.

Effect of electrolyte composition on the morphological structures of dendritic copper powders prepared by a spontaneous galvanic displacement reaction

Dendritic copper powders are highly desirable in many applications, including electromagnetic interference shielding and conductive pastes, because of low cost and high conductivity. We prepared dendritic copper powders using the galvanic displacement reaction between the Al and Cu-ions in aqueous solution. This method is very simple and spontaneous at room temperature. During the process, the morphology of the copper powders is strongly affected by several variables, such as the displacement reaction rate and the amount of hydrogen evolution due to the reduction of proton. The effect of the different composition of electrolytes to morphological changes of copper powders was investigated in this study. In addition, the effects of concentration of chlorine ion, pH, termination time, and additives were monitored, which resulted in different morphology. Considering different applications, such as sensors, catalysts, and conductive pastes, the controllability of the morphology of dendritic copper powders plays an important role in achieving high performance in desired applications.

The electrochemical 4-chlorophenol sensing properties of a plasma-treated multilayer graphene modified photolithography patterned platinum electrode

The present work describes the electrochemical 4-chlorophenol (4-CP) sensing properties of multilayer graphene samples (MLG). In order to enhance the presence of oxygen functional groups and to increase the edge plane defects, oxygen plasma treatment is adopted. Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterizations are used to investigate the effect of plasma treatment on MLG. Compared to pristine MLG, the oxygen plasma treated one shows increased oxidation current towards 4-CP. The sensor data exhibit high sensitivity and stability with high anti-interference property in the presence of other phenolic compounds including phenol, bisphenol, 2,3-chlorophenol, 2,3,4-nitrophenol and inorganic ions.