Electrospinning has been recognized as one of the most efficient techniques for producing non-woven fiber webs on the order of several hundreds of nanometers by electrically charging a suspended droplet of polymer solution with/without inorganic precursors or melt. Various types of materials with a high degree of porosity, a large surface area, superior mechanical properties and modified surface functionalities, can be electrospun into nanofiber structures. These materials include polymeric nanofibers as well as metallic and metal-oxide nanofibers which are prepared by a subsequent heat treatment in a reducing or oxidizing atmosphere of metal salt precursor/polymer composite fibers. In particular, the simplicity of the process combined with the possibility of large-scale production through the use of multiple-nozzles (> 10,000 pieces) makes this process very attractive and therefore opens up new commercial markets for diverse applications. In this presentation, I summarize recent progress and a collection of advances, particularly focused on the synthesis, characterization, and utilization of electrospun nanofibers. I will end my presentation by suggesting possible future research direction and potential suitability of 3D nanofibers for applications in colorimetric sensors, exhaled breath gas analyzing sensors for early stage disease diagnosis, and nanocatalysts for next generation energy storage devices.