Activatable photoacoustic probes efficiently combine the high spatial resolution and penetration depth of ultrasound with the high optical contrast and versatility of molecular imaging agents. Our approach is based on photoacoustic probing of the excited-state lifetime of methylene blue (MB), a fluorophore widely used in clinical therapeutic and diagnostic applications. Upon aggregation, static...

Photoacoustic imaging is an emerging modality that overcomes to a great extent the resolution and depth limitations of optical imaging while maintaining relatively high-contrast. However, since many diseases will not manifest an endogenous photoacoustic contrast, it is essential to develop exogenous photoacoustic contrast agents that can target diseased tissue(s). Here we present a novel photoa...

Some of the challenges in translating photoacoustic (PA) imaging to clinical applications includes limited view of the target tissue, low signal to noise ratio and the high cost of developing real-time systems. Acoustic lens based PA imaging systems, also known as PA cameras are a potential alternative to conventional imaging systems in these scenarios. The 3D focusing action of lens enables re...

A photoacoustic nanoprobe is self-assembled from human serum albumin and two types of dye molecules, one is inert to pH and the other is pH sensitive. This probe and the quantitative ratiometric photoacoustic pH imaging method are shown to have high safety, be easy-to-operate, and have depth-independent accuracy for real-time in vivo pH imaging of entire tumors. These features make them promisi...

Optical nanomaterials with intense absorption in near-infrared (NIR) region hold great promise for biomedical applications such as photothermal therapy (PTT) and photoacoustic imaging (PAI). In this work, we report mesoporous carbon nanospheres (Meso-CNs) with broadband and intense absorption in the UV-Vis-NIR region (300-1400 nm) and explore their potential as a multifunctional platform for ph...

An innovative very fast non-contact imaging technique for Photoacoustic Tomography is introduced. It is based on holographic optical speckle detection of a transiently altering surface topography for the reconstruction of absorbing targets. The surface movement is obtained by parallel recording of speckle phase changes known as Electronic Speckle Pattern Interferometry. Due to parallelized 2-D ...

Achieving label-free, molecular-specific imaging with high spatial resolution in deep tissue is often considered the grand challenge of optical imaging. To accomplish this goal, significant optical scattering in tissues has to be overcome while achieving molecular specificity without resorting to extrinsic labeling. We demonstrate the feasibility of developing such an optical imaging modality b...

Several detection methods have been explored for photoacoustic and ultrasound imaging of biological tissues. Piezoelectric transducers are commonly used, which require contact with the sample and have limiting bandwidth characteristics. Interferometry detection exhibits improved bandwidth characteristics and resolution, yet generally require complicated optics and the incorporation of a contact...