A novel technique for the label-free analysis of micro and nanoparticles including biomolecules using optical micro
cavity resonance of whispering-gallery-type modes is being developed. Various schemes of the method using both
standard and specially produced microspheres have been investigated to make further development for microbial
application. It was demonstrated that optical resonance under optimal geometry could be detected under the laser power
of less 1 microwatt. The sensitivity of developed schemes has been tested by monitoring the spectral shift of the
whispering gallery modes. Water solutions of ethanol, ascorbic acid, blood phantoms including albumin and HCl,
glucose, biotin, biomarker like C reactive protein so as bacteria and virus phantoms (gels of silica micro and
nanoparticles) have been used.
Structure of resonance spectra of the solutions was a specific subject of investigation. Probabilistic neural network
classifier for biological agents and micro/nano particles classification has been developed. Several parameters of
resonance spectra as spectral shift, broadening, diffuseness and others have been used as input parameters to develop a
network classifier for micro and nanoparticles and biological agents in solution. Classification probability of
approximately 98% for probes under investigation have been achieved.
Developed approach have been demonstrated to be a promising technology platform for sensitive, lab-on-chip type
sensor which can be used for development 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.