A novel emerging technique for the label-free analysis of nano particles including biomolecules using optical
micro cavity resonance is being developed. Various schemes based on a mechanically fixed microspheres as
well as microspheres melted by laser on the tip of a standard single mode fiber have been investigated to
make further development for microbial application.
Water solutions of ethanol, HCl, glucose, vitamin C and biotin have been used to test refractive index changes
by monitoring the magnitude of the whispering gallery modes spectral shift. Particular efforts were made for
effective fixing of the micro spheres in the water flow, an optimal geometry for micro resonance observation
and material of microsphere the most appropriate for microbial application. Optical resonance in free micro
spheres from PMMA fixed in micro channels produced by photolithography has been observed under the
laser power of less then 1 microwatt. Resonance shifts of C reactive protein water solutions as well as
albumin solutions in pure water and with HCl modelling blood have been investigated. Introducing controlled
amount of glass gel nano particles into sensor microsphere surrounding were accompanied by both correlative
resonance shift (400 nm in diameter) and total reconstruct of resonance spectra (57 nm in diameter).
Developed schemes have been demonstrated to be a promising technology platform for sensitive, lab-on-chip
type sensor of diagnostic tools for different biological molecules, e.g. proteins, oligonucleotides,
oligosaccharides, lipids, small molecules, viral particles, cells as well as in different experimental contexts
e.g. proteomics, genomics, drug discovery, and membrane studies.