Though graphitic carbons are commercially available for various electrochemical processes, their performance is limited in terms of various electrochemical activities. Recent experiments on layered carbon materials, such as graphene, demonstrated an augmented performance of these systems in all electrochemical activities due to their unique electronic properties, enhanced surface area, structure and chemical stabilities. Moreover, flexibility in controlling electronic, as well as electrochemical activities by heteroatom doping brings further leverage in their practical use. Here, we study the electron transfer kinetics of fluorinated graphene derivatives, known as fluorinated graphene oxide (FGO) and its reduced form, RFGO. Enhanced electron transfer kinetics (heterogeneous electron transfer (HET)) is observed from these fluorinated systems in comparison to their undoped systems such as graphene oxide (GO) and reduced GO. A detailed study has been conducted using standard redox probes and biomolecules revealing the enhanced electro-catalytic activities of FGO and RFGO, and electron transfer rates are simulated theoretically. This study reveals that fluorine not only induces defects in graphitic lattice leading to an enhanced HET process but also can modify the electronic structure of graphene surface.

One-dimensional Co3O4 nanorods, two-dimensional nanosheets and three-dimensional nanocubes were synthesized; the effect of the morphology on their electrocatalytic activities was studied.

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The design of hierarchical metal oxide nanostructured systems has emerged as an effective strategy for improving the performance of hydrogen (H 2 ) gas sensing to facilitate a H 2 economy. H 2 gas sensors that can operate at elevated temperatures (≥500 °C) are necessary for advanced combustion monitoring and emission control in the automotive industry. Here we report on a hierarchical threedimensional nickel and cobalt oxide nanomaterial as an efficient high-temperature gas sensor for H 2 detection. Our study reveals that the response of the nickel−cobalt oxides strongly depends on the morphology and ratio of Ni/Co. The flower-like NiO nanomaterial demonstrates a p-type response to H 2 at 300−500 °C and an n-type response to H 2 gas at 600 °C. The developed nickel−cobalt oxide sensor exhibits a unique performance and superior sensitivity at elevated temperatures of ∼500 °C but a negligible response at 300−400 °C. A high surface area with small nanopores and a sensitive change in the crystalline nature at >500 °C make this new nickel−cobalt oxide nanomaterial distinctive for the detection of H 2 at such high temperatures. The novel H 2 gas sensor developed in this study exhibits excellent sensitivity, selectivity against various gaseous mixtures, and high stability, demonstrating its promising practical functionality.

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An innovative one-pot approach for the scalable production of novel interconnected reduced graphene oxide (IC-RGO) is demonstrated, and we name it the streamlined Hummers method (SHM). The formed IC-RGO represents a new type of three-dimensional platform, promising for many graphene related energy, environmental and medical applications.

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Neurotransmitters are molecules that transfer chemical signals between neurons to convey messages for any action conducted by the nervous system. All neurotransmitters are medically important; the detection and analysis of these molecules play vital roles in the diagnosis and treatment of diseases. Among analytical strategies, electrochemical techniques have been identified as simple, inexpensive, and less time-consuming processes. Electrochemical analysis is based on the redox behaviors of neurotransmitters, as well as their metabolites. A variety of electrochemical techniques are available for the detection of biomolecules. However, the development of a sensing platform with high sensitivity and selectivity is challenging, and it has been found to be a bottleneck step in the analysis of neurotransmitters. Nanomaterials-based sensor platforms are fascinating for researchers because of their ability to perform the electrochemical analysis of neurotransmitters due to their improved detection efficacy, and they have been widely reported on for their sensitive detection of epinephrine, dopamine, serotonin, glutamate, acetylcholine, nitric oxide, and purines. The advancement of electroanalytical technologies and the innovation of functional nanomaterials have been assisting greatly in in vivo and in vitro analyses of neurotransmitters, especially for point-of-care clinical applications. In this review, firstly, we focus on the most commonly employed electrochemical analysis techniques, in conjunction with their working principles and abilities for the detection of neurotransmitters. Subsequently, we concentrate on the fabrication and development of nanomaterials-based electrochemical sensors and their advantages over other detection techniques. Finally, we address the challenges and the future outlook in the development of electrochemical sensors for the efficient detection of neurotransmitters.