We report on pump-probe mode-mismatched photothermal lens experiments of metallic nanoparticles water solutions.
We show that metallic nanoparticles colloids exhibit nonlinear absorption effects related to attraction or repulsion forces
that result from the interaction with the electromagnetic radiation. Gold and iron oxide nanoparticles show a double
peak Z-scan shape that is associated to the presence of attraction forces. We calibrate the experiment using the linear
absorption values of the samples obtaining their corresponding nonlinear absorption coefficients.
We report on a new application of laser induced breakdown spectroscopy (LIBS) for the diagnosis of diseases such as
ovarian cancer. We perform detection of ovarian cancer biomarker CA 125 based on LIBS measurements. Immunoconjugated
Silicon particles are incubated with the affinity agarose beads carrying CA125 molecules. In the competitive
affinity method Si particles carrying IgG molecules are pre-incubated with CA125. This pre-incubation decreases the
numbers of free IgG molecules available for consequent interaction with the affinity beads. Thus less Si particles are
attached to the agarose beads and consequently smaller Si peak area is measured by LIBS. We demonstrate a limit-ofdetection
about 30 ppb for model protein avidin. We use two-element coded micro-particles to yield spectroscopic
emission code using LIBS. We show that LIBS-based data collecting technique provides methodology for identification
of biomarkers and cost-effective device for future clinical applications.
We report on Fourier transform spectra of deuterated proteins: Bovine Serum Albumin, Leptin, Insulin-like Growth
Factor II, monoclonal antibody to ovarian cancer antigen CA125 and Osteopontin. The spectra exhibit changes in
the relative amplitude and spectral width of certain peaks. New peaks not present in the non-deuterated sample are
also observed. Ways for improving the deuteration of proteins by varying the temperature and dilution time are
discussed. We propose the use of deuterated proteins to increase the sensitivity of immunoassays aimed for early
diagnostic of diseases most notably cancer.