Synthesis and sensing applications of metal nanoclusters: a frontier to cancer diagnostics

One of the most extensively studied research areas in cancer treatment is the rapid diagnosis of cancer, which is crucial for combating this deadly disease. Over the years, nanotechnology's remarkable capabilities have paved the way for groundbreaking advancements in cancer diagnosis. Among nanomaterials, nanoclusters have been distinguished due to their small size, effective surface functionalization, and optical characteristics, which make them a potential candidate for revolutionizing cancer detection strategies. The fabrication process of nanoclusters requires control over various factors such as shape, surface, and size characteristics that contribute to their unique electronic and optical properties, tailoring the nanocluster features that make them the best fit for diagnostic applications. Moreover, functionalizing the nanoclusters with various functional groups or targeting ligands (such as antibodies, aptamers, or peptides) enhances their stability, biocompatibility, and capacity for targeted interactions. Owing to their unique optical and surface properties and versatile functionalization, these nanoclusters significantly enhance the sensitivity, specificity, and precision in the detection of cancer cells. This review paper covers the different synthesis methods of the nanoclusters, tailoring the nanoclusters for cancer diagnosis, various types of metallic nanoclusters, and their role in cancer diagnosis, highlighting their unique properties, and diagnostic modalities. We also discuss the current state of the field, contemporary advancements, and existing obstacles, providing insights into the future directions of nanocluster-based cancer diagnostics.