Porous nanomaterials like electrospun nanofibers and paper-based scaffolds have revolutionized nanomedicine and diagnostics. Electrospinning is a sophisticated method for making nanofibrous structures with a large surface area and variable porosity. Thus, these structures are promising nanomedicine drug delivery platforms. Electrospun nanofibers allow regulated medication release, allowing precise treatment kinetics and decreasing side effects. Electrospinning’s flexibility allows it to include a wide range of bioactive substances, enabling the fabrication of customized therapeutic formulations. Paper-based scaffolds produce porous nanoparticles cost-effectively and creatively, which has biological applications. Intentionally constructed paper substrates have intrinsic porosity, enabling medication or imaging agent inclusion. Integration helps regulate chemical release and enhances diagnostics. Due to their simplicity and efficiency, paper-based scaffolds are the ideal choice for point-of-care diagnostics. The provided platform is mobile and user-friendly. This chapter examines the many uses of porous nanomaterials, focusing on electrospun nanofibers and paper-based scaffolds in nanomedicine and diagnostics. Versatility, compatibility with living organisms, and customizable capabilities give innovative therapeutic and diagnostic platforms enormous potential.