Hyperspectral absorption microscopy using photoacoustic remote sensing

Area of Science:

• Biomedical Optics
• Spectroscopy
• Photoacoustics

Background:

• Optical absorption spectroscopy and imaging are crucial for biological tissue analysis.
• Existing methods may have limitations in non-destructive characterization of endogenous contrast.
• Photoacoustic remote sensing offers a unique detection architecture.

Purpose of the Study:

• To describe an improved method for remote optical absorption spectroscopy and hyperspectral imaging.
• To leverage photoacoustic remote sensing for enhanced characterization of endogenous chromophores.
• To demonstrate the sensitivity and efficacy of the developed technique.

Main Methods:

• Utilized a nanosecond tunable source providing photoacoustic excitation wavelengths from 210 nm to 1550 nm.
• Employed the photoacoustic remote sensing detection architecture for improved measurements.
• Applied the technique to characterize water's infrared absorption spectrum, a live chicken embryo model, and murine adipose tissue.

Main Results:

• Successfully characterized salient endogenous chromophores including DNA, hemeproteins, and lipids.
• Demonstrated high sensitivity by accurately measuring the infrared absorption spectrum of water.
• Effectively recovered cell nuclei, oxygen saturation in a live chicken embryo, and adipocytes from tissue samples.

Conclusions:

• The hyperspectral photoacoustic remote sensing technique offers effective non-destructive characterization of endogenous contrast.
• This method shows significant potential for advanced biomedical imaging and visualization.
• Further investigation into this technique may lead to novel diagnostic and research tools.