Deep-tissue chemical imaging is essential for many biomedical applications. Here, we present a shortwave infrared photothermal (SWIP) microscope for millimeter-deep vibrational imaging with micron-resolution and nanoparticle detection sensitivity. By using short-wave infrared light for overtone excitation of CH bonds and photothermal probing, our modality can reach millimeter deep into scattering phantom and tissue. With a fast digitization method, we showed that in our setting the photothermal signal amplitude is 100 times larger than photoacoustic thus enabling higher sensitivity. SWIP can resolve intracellular lipids in tumor spheroid and layered structure in the liver, skin, and brain tissue.
Photoacoustic (PA) neural modulation has gained attention for its non-genetic, precise, and minimally damaging properties. Existing PA methods relay on thermal expansion of the absorber/ elastomer matrix. Usually, a visible or near-infrared (NIR) laser is used to excite the electronic transition of the absorber. Here, we present a mid-infrared photoacoustic (MIPA) emitter through vibrational excitation in polydimethylsiloxane (PDMS). A transparent film with 37.5 times enhancement of PA performance compared to carbon nanotube based PA emitter is obtained due to bypass the thermal conduction process. Both wide-field (100μm) and single cell MIPA neural stimulation were achieved and validated through calcium imaging.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.