Photoacoustic imaging of potassium level in breast tumors

We present a noninvasive imaging approach for quantifying extracellular potassium (K⁺) in breast tumors using multi-wavelength photoacoustic chemical imaging (PACI) and a potassium-sensitive nanoprobe (SDKNP). The breast tumors were imaged at five wavelengths, generating spatial K⁺ maps validated against ICP-MS measurements. Larger tumors exhibited significantly elevated extracellular K⁺ levels, consistent across both imaging and analytical methods. This work establishes PACI as a promising tool for mapping ionic biomarkers in vivo and offers new opportunities for understanding the tumor microenvironment and predicting immunotherapy response.