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Carbon nanofiber-based electrodes are generally embedded with either metal oxides or two-dimensional materials to enhance their specific capacitance and rate performance. For the first time, a flexible carbon nanofiber electrode consisting of metal oxide (RuO2) and two-dimensional MXene was prepared to realize the synergetic effect on the electrochemical performance. This ternary composite electrode was prepared by electrospinning RuO2, and MXene dispersed polyacrylonitrile precursor solution, followed by thermal treatment. The distribution of RuO2 nanoparticles and delaminated MXene sheets within a carbon nanofiber matrix was examined using X-ray diffraction and transmission electron microscopy, while morphological analysis was carried out using scanning electron microscopy. The electrode with pseudocapacitive RuO2 and layered MXene facilitated charge storage by faradic reactions and intercalation of electrolyte ions. Electrochemical studies demonstrated that the prepared ternary composite electrodes exhibit a specific capacitance of 322 F g-1 with a capacitance retention of 90% after 2500 cycles at 1 A g-1. Additionally, the ternary composite showed an excellent rate capability with a minimal drop in capacitance when the current density was varied from 2 A g-1 to 10 A g-1.

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Aromatic amines such as aminobiphenyl (ABP) isomers have been studied by various research groups as putative bladder carcinogens. Among the three isomers, 4-ABP and 3-ABP are reported as human carcinogens and the carcinogenicity of 4-ABP has been shown to be greater than that of 3-ABP [ Raman spectroscopy is capable of detecting ABP isomers at very low concentrations via surfaceenhanced Raman scattering (SERS), in which the Raman signal is enhanced by the presence of silver nanoparticles that allow the adsorption of analytes. The shape and size of the silver nanoparticles play an important role in influencing the magnitude of the signal enhancement [5]. Silver and gold colloidal nanoparticles prepared under different synthesis and centrifugation conditions have been characterized by transmission electron microscopy (TEM) in conjunction with the "Image J" image processing software in order to correlate the physical characteristics of particles with the degree of Raman signal enhancement. It was found that nebulization of colloidal nanoparticles using either a pneumatic or ultrasonic nebulizer was suitable for preparing TEM specimen grids that gave good images with no appreciable overlap or aggregation of nanoparticles. Further analysis of the ABP isomers by Raman microscopy also showed that the SERS enhancement factor of 4-ABP is significantly larger than those of 2-ABP and 3-ABP for both gold and silver colloids. The spectral differences of the Raman spectra of the neat ABP isomers versus their SERS spectra will be described with regard to the changes in the intensities, positions, and shapes of the peaks.Raman signal enhancement is highly dependent on the rate of 4-ABP adsorption onto the silver nanoparticles. The SERS signal was found to increase from the time of mixing the colloid and 4-ABP up to 4 hours followed by a gradual decrease over a 24-hour period. The adsorption kinetics is further studied by solid phase micro extraction in conjunction with gas chromatography-mass spectrometry (GC-MS) to provide a better understanding of the adsorption process among the three ABP isomers in order to develop an optimal method for their analysis.

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