Diagnostic Drugs: Concept, Current Status, and Challenges in New-Age Diagnosis Platform Development.

Unmet medical needs form the basis for the discovery of diagnostic tools and drugs for diseases that elude existing treatment options. Herein, we provide a perspective on the current trends in diagnosis and treatment using conventional and state-of-the-art diagnostic drugs. Our report highlights the evolution of diagnosis and therapy, more so in the form of after pulmonary combining the drug discovery process with diagnostics known as "drug-diagnostic codevelopment", which has opened the doors for precision medicine. Modern-age diagnostic drugs, such as conjugating a drug to fluorophores via a covalent bond, have the potential to both detect and treat diseases. However, fluorescence quenching in solutions is a major bottleneck. This can be addressed using quantum dots (QDs) conjugated to drugs such as cadmium telluride (CdTe) QDs conjugated to 5-fluorouracil (5-FU), naproxen, and celecoxib. However, these conjugates could get aggregated, and they may also pose health risks due to the involvement of heavy metals. Supramolecular chemistry could play a pivotal role in addressing both the aggregation and safety issues without compromising its utility. The discovery of supramolecular aggregation-induced emission (AIE) probes and their applications to drug conjugates have been demonstrated in a few studies. Taken together, this report summarizes the significance of advanced diagnostic drugs possessing AIE-conjugated probes for use in diagnosis and therapy.