The beginning of the twenty-first century saw advancements in all areas of life, including medicine and nanotechnology. This review will look at the most recent advances in nanomaterials for diagnostics and treatments. The emphasis is on the application of nanofibers, nanosensors, and quantum dots (QDs) in medication delivery, neuron regeneration, chemical detection, and microelectrode probes. The manufacture of implantable nanofibers and nanosensors based on QDs, and their application-specific features impacting the interface with targeted brain cells were described. The collaborative efforts have helped us to understand the potential of nanostructured materials in fabrication to overcome the limits of micro and bulk materials in treatments and diagnostics. These advancements will eventually lead to using nanostructures, including nanofibers and nanosensors, in high throughput cutting-edge applications. Only when extensive safety investigations have been completed may the use of nanomaterials on an industrial basis be viable. This review discusses the recent advances in the usage of nanostructures and nanoparticles (NPs) for diagnostics and treatments, with a special focus on nanofibers, nanosensors, and quantum dots (QDs) applications in drug delivery, nerve regeneration, chemical detection, and microelectrode probes.