A biosensor based on an array of vertically aligned carbon nanofibers (CNFs) grown by plasma enhanced chemical vapor deposition is found to be effective for the simultaneous detection of dopamine (DA) and serotonin (5-HT) in the presence of excess ascorbic acid (AA). The CNF electrode outperforms the conventional glassy carbon electrode (GCE) for both selectivity and sensitivity. Using differential pulse voltammetry (DPV), three distinct peaks are seen for the CNF electrode at 0.13 V, 0.45 V, and 0.70 V for the ternary mixture of AA, DA, and 5-HT. In contrast, the analytes are indistinguishable in a mixture using a GCE. For the CNF electrode, the detection limits are 50 nM for DA and 250 nM for 5-HT.

Facile and reproducible SERS signals from Shewanella oneidensis were obtained utilizing silver nanoparticles (AgNPs) and silver nanowires (AgNWs). Additionally, SERS images identify the distribution of SERS hot-spots. One important observation is the synergistically enhanced SERS signal when AgNPs and AgNWs are used in conjunction, due to constructively enhanced electromagnetic field.

This study presents composite electrode materials based on graphene oxide (GO) and transition metal oxide nanostructures for supercapacitor applications. Electrophoretic deposition of GO on a conductive substrate was used to form reduced graphene oxide (rGO) films through chemical reduction. The specific capacitance of the rGO was calculated up to 117 F/g at 100 mV/s scan rate from KOH (1 M) electrolyte using an Ag/AgCl reference electrode. The strong interaction of GO with Co3O4 and MnO2 nanostructures was demonstrated in the self-assembled Langmuir–Blodgett monolayer composite, showing the potential to fabricate thin film supercapacitor electrodes without using binder materials. This two-step process is nontoxic and scalable and holds promise for improved energy density from redox capacitance in comparison with the conventional double layer supercapacitors.