The ability to modulate cellular electrophysiology is fundamental to the investigation of development, function, and disease. Currently, there is a need for remote, nongenetic, light-induced control of cellular activity in two-dimensional (2D) and three-dimensional (3D) platforms. Here, we report a breakthrough hybrid nanomaterial for remote, nongenetic, photothermal stimulation of 2D and 3D neural cellular systems. We combine one-dimensional (1D) nanowires (NWs) and 2D graphene flakes grown out-of-plane for highly controlled photothermal stimulation at subcellular precision without the need for genetic modification, with laser energies lower than a hundred nanojoules, one to two orders of magnitude lower than Au-, C-, and Si-based nanomaterials. Photothermal stimulation using NW-templated 3D fuzzy graphene (NT-3DFG) is flexible due to its broadband absorption and does not generate cellular stress. Therefore, it serves as a powerful toolset for studies of cell signaling within and between tissues and can enable therapeutic interventions.

There is an intrinsic repulsion between glass and cell surfaces that allows noninvasive scanning ion conductance microscopy (SICM) of cells and which must be overcome in order to form the gigaseals used for patch clamping investigations of ion channels. However, the interactions of surfaces in physiological solutions of electrolytes, including the presence of this repulsion, for example, do not obviously agree with the standard Derjaguin−Landau− Verwey−Overbeek (DLVO) colloid theory accurate at much lower salt concentrations. In this paper we investigate the interactions of glass nanopipettes in this high-salt regime with a variety of surfaces and propose a way to resolve DLVO theory with the results. We demonstrate the utility of this understanding to SICM by topographically mapping a live cell's cytoskeleton. We also report an interesting effect whereby the ion current though a nanopipette can increase under certain conditions upon approaching an insulating surface, rather than decreasing as would be expected. We propose that this is due to electroosmotic flow separation, a high-salt electrokinetic effect. Overall these experiments yield key insights into the fundamental interactions that take place between surfaces in strong solutions of electrolytes.

Smart bioelectronics fabricated from nanocarbons have the potential to enable seamless integration with electrogenic cells and tissues.

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Modified fyke nets have long been used by fisheries managers to assess species composition and evaluate population characteristics of individual species. Despite their widespread use, only recently have recommendations for standard fyke net specifications been made. Therefore, we evaluated species composition and catch rates, size structure, and sample size requirements for bluegill (Lepomis macrochirus), black crappie (Poxomis nigromaculatus), and white crappie (P. annularis) in seven Iowa lakes in the fall of 2009 using two different fyke nets. Fyke net specifications followed a recently recommended standard design and that currently used by Iowa Department of Natural Resources (IDNR). Overall, the standard fyke net sampled more individuals and species than the IDNR net. Additionally, mean catch rates of the focal species were consistently higher with the standard fyke net. Size structure comparisons were limited by fewer than 125 stock-length fishes sampled in several lakes, but when comparison was possible, size structure was similar between the fyke net types. The number of samples needed to obtain at least 125 stock-length individuals with standard fyke nets was consistently lower than that for IDNR fyke nets for all species.