It has been shown that non-resonant multiphoton photoacoustic spectroscopy (NMPPAS) has a great
potential to be used as a high resolution surgical guidance technique during brain tumor surgery due to its
ability of non-invasive or minimally invasive tumor differentiation. However, for experimental purposes
associated with method validation, the use of real tissues is not always ideal because of issues such as
availability, safety, storage, chemical doping, necessary control of size and shape, etc. To overcome these
issues, tissue phantoms made from animal tissues and/or biochemical constituents, are often employed for
such analyses. This work demonstrates the ability to develop and characterize gelatin based tissue phantoms
with comparable optical and acoustic properties to real tissues by doping the phantoms with a scattering
substance, 0.3 μm diameter Al2O3 particles. Using these phantoms, light scattering coefficients (μs) of 39 cm-1
have been generated, which are comparable to real brain tissue, thus making them a great alternative to real
tissue for validation studies.
In addition, this work also investigates the non-fluorescent species NAD+ found in the tissues, to
evaluate its potential for being detected by NMPPAS. NMPPAS spectra of NAD+ shows a very promising
beginning to determine other chemical species such as flavins, collagen, tryptophan, etc responsible for
NMPPAS spectral signatures, associated with tumorogenesis.