(1) The formulated nanoparticles showed a large (10-fold) NIR-II fluorescence enhancement and a detection limit of 72 nM(2) With TfR targeting properties endowed by T7 decoration, the nanoparticles were able to map MGO in vivo in real time(3) TM-IONPs were found to be capable of visualizing subtle abnormalities in MGO levels in AD brains and differentiating AD mice from normal mice by the 24.2-fold enhancement in NIR-II fluorescence for the first time.