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Nanostructures and nanostructured substrates show enhanced coupling to artificial membranes, cells, and tissue. Such nano-bio interfaces offer better sensitivity and spatial resolution as compared to conventional planar structures. Here we report the electrical properties of silicon nanowires (SiNWs) interfaced with embryonic chicken hearts and cultured cardiomyocytes. In addition, by utilizing the bottom-up approach, we extend our work to the sub-cellular regime, and interface cells with the smallest reported device ever and thus exceed the spatial and temporal resolution limits of existing electrical recording techniques. The exceptional synthetic control and flexible assembly of nanowires provides powerful tools for fundamental studies and applications in life science, and opens up the potential of merging active transistors with cells such that the distinction between nonliving and living systems is blurred.

Hybrid materials, composed of organic and inorganic components, have shown to be useful in a variety of optoelectronic applications including electrochromic devices, light emitting diodes, photodetectors and solar cells. In such systems, the key processes of charge and/or energy transfer occur across the organic-inorganic interface and are therefore predominantly influenced by interfacial properties such as surface area, chemical composition and physical interactions. Inherent chemical incompatibility of the organic and inorganic components limits the interfacial surface area, but can be overcome by temperature, use of co-solvents, substrate surface chemistry, or use of suitable compatibilizers. Here we show that the nature of the compatibilizer can be used to direct contact and interactions at the organic-inorganic interface, thus governing the optoelectronic processes across the interface. Few examples will be discussed in which highly ordered conjugated polymer/metal oxide films were prepared using surfactant structure-directing agents (SDAs) with different molecular weights and architectures on flat substrates and in confined spaces. A combination of small X-ray scattering (SAXS), electron microscopy (SEM and TEM), solid-state NMR spectroscopy, and energy-filtered high resolution TEM (EFHRTEM) was used to determine the hierarchical structural ordering and orientation of the materials; and show that the extent to which the conjugated polymer interacts with the hydrophilic metal oxide framework depends on the molecular weight and architecture of the surfactant. Importantly, the molecular-level interactions between the different SDA blocks, the conjugated polymer and the metal oxide framework, are correlated with steady-state and timeresolved photoluminescence measurements of the photo-excitation dynamics of the conjugated polymer and macroscopic photocurrent generation in photovoltaic devices. Therefore, molecular understanding of the compositions and chemical interactions at organic-inorganic interfaces are shown to enable the design, synthesis and control of the photo-physcial properties of hybrid functional materials