The advantage of this polymer is that it degrades fast in the body. The first drug delivered to the brain using nanoparticles was hexapeptide Dalargin. Sphere-shaped, amorphous particles that do not aggregate can be used to make nanoparticles, making intravenous administration of them safe. Overall toxicity of the formulation is decreased since no cosolvent is used to solubilize the drug. There must be at least one dimension in a nanocluster's size distribution that ranges between 1 and 10 nanometres. Nano powders are collections, clusters, or aggregates of nanoparticles. Nanocrystals are widely used to describe single crystals or single domain ultrafine particles with a diameter less than a nanometre. Nanoparticle research is now a booming field because of the plethora of potential uses in the fields of healthcare, optics, and electronics. The biosensor reading device interfaces with the supporting electronics or signal processors that are largely in charge of the user-friendly presentation of the results. This is occasionally the most expensive component of the sensor device, but a user-friendly display that incorporates the transducer and sensitive element is still technically feasible (holographic sensor). The readers are typically produced and custom-designed to fit the various biosensor operating principles.