pH dependence of perturbed angular correlation in DOTA chelated $$^{111}$$In measured with ring-shape gamma-ray detectors

Abstract The conventional nuclear medical imaging, such as PET and SPECT, visualizes the accumulation of radioisotopes in the human body and has been widely used for diagnosis of cancer and other diseases. Perturbed angular correlation is a powerful sensing tool detecting local electro-magnetic environment and has been used for chemical analysis or nuclear physics research. The use of perturbed angular correlation in nuclear medicine is recently proposed and pH sensing capability with liquid $$^{111}$$ 111 In has been confirmed. In more practical applications, DOTA based radioisotope labeled drug delivery is common in nuclear medicine. This study aims to characterize the pH dependance of perturbed angular correlation in Psyche-DOTA chelated $$^{111}$$ 111 In with the custom ring-shape gamma-ray detectors. The observed transition in anisotropy of cascade gamma-ray emission can contribute to the detection of a specific phenomenon changing pH inside the human body.