1 research outputs found
Calcium Sensor for Photoacoustic Imaging
We
introduce a selective and cell-permeable calcium sensor for
photoacoustics (CaSPA), a versatile imaging technique that allows
for fast volumetric mapping of photoabsorbing molecules with
deep tissue penetration. To optimize for Ca<sup>2+</sup>-dependent
photoacoustic signal changes, we synthesized a selective metallochromic
sensor with high extinction coefficient, low quantum yield, and high
photobleaching resistance. Micromolar concentrations of Ca<sup>2+</sup> lead to a robust blueshift of the absorbance of CaSPA,
which translated into an accompanying decrease of the peak photoacoustic
signal. The acetoxymethyl esterified sensor variant was readily
taken up by cells without toxic effects and thus allowed us for the
first time to perform live imaging of Ca<sup>2+</sup> fluxes in genetically
unmodified cells and heart organoids as well as in zebrafish larval
brain via combined fluorescence and photoacoustic imaging