Isometrically Resolved Photoacoustic Microscopy Based on Broadband Surface Plasmon Resonance Ultrasound Sensing.
Photoacoustic microscopy (PAM) can measure optical absorption-based molecular specificities within tissues. Despite the diffraction-limited lateral resolution in optical-resolution photoacoustic microscopy (OR-PAM), the ongoing challenge is poor axial resolution because of an insufficient ultrasound detection bandwidth, which hampers PAM volumetric imaging. We propose polarization-differential surface plasmon resonance (SPR) sensing for broadband and high-sensitivity photoacoustic (PA) detection, allowing OR-PAM with comparable resolution along lateral and axial directions. This sensor possesses an estimated noise-equivalent-pressure sensitivity of ∼477 Pa over an approximately linear pressure response up to 107 kPa. Moreover, an improved PA detection bandwidth of ∼173 MHz permits an axial resolution (∼7.6 μm) that approaches the lateral resolution (∼4.5 μm) of our OR-PAM system. The capability in spatially isometric micrometer-scale resolution enables in vivo volumetric label-free imaging of the microvasculature of a mouse ear. The SPR sensing technology promises broader applications of PAM in biomedical studies such as microcirculation.
['Song|Wei|W|http://orcid.org/0000-0003-2679-1069', 'Peng|Liangliang|L|', 'Guo|Guangdi|G|', 'Yang|Fan|F|', 'Zhu|Yan|Y|', 'Zhang|Chonglei|C|', 'Min|Changjun|C|', 'Fang|Hui|H|', 'Zhu|Siwei|S|', 'Yuan|Xiaocong|X|http://orcid.org/0000-0003-2605-9003']
D000818:Animals D004423:Ear D051379:Mice D008853:Microscopy D055806:Microvessels D057054:Molecular Imaging D061088:Photoacoustic Techniques D020349:Surface Plasmon Resonance D014463:Ultrasonography
photoacoustic microscopy surface plasmon resonance sensitivity broad bandwidth in vivo imaging spatial resolution