Background: The invention of enhanced Raman scattering by adsorbing molecules on nanostructured metal
surfaces is a milestone in the development of spectroscopic and analytical techniques. Important experimental and
theoretical efforts were geared towards understanding the Surface Enhanced Raman Scattering effect (SERS) and evaluating
its significance in a wide range of fields in different types of ultrasensitive sensing applications.
Methods: Metal nanoclusters have been widely studied due to their unique structure and individual properties, which place
them among single metal atoms and larger nanoparticles. In general, the nanoparticles with a size less than 2 nm is defined
as nanoclusters (NCs) and they possess distinct optical properties. In addition, the excited electrons from absorption bands
results in the emission of positive luminescence associated to the quantum size effect in which separate energy levels are
Results: It is demonstrated that fluorescent based SERS investigations of metal nanoparticles have showed more
photostability, high compatibility, and good water solubility, has resulted in high sensitivity, better imaging and sensing
experience in the biomedical applications.
Conclusion: In the present review, we report recent trends in the synthesis of metal nanoclusters and their applications in
biosensing and bio-imaging applications due some benefits including cost-effectiveness, easy synthesis routes and less
consumption of sample volumes. Outcomes of this study confirms that SERS based fluorescent nanoclusters could be one
of thrust research areas in biochemistry and biomedical engineering.