Significance: Drug development for Alzheimer’s disease (AD) has been largely unsuccessful to date. Although numerous agents are reportedly effective in vitro, only an inadequate number of them have been tested in vivo, partially because of the lack of reliable and cost-efficient imaging methods to monitor their in vivo therapeutic effectiveness. Several amyloid beta (Aβ)-specific PET tracers have been used for clinical studies. However, their application for monitoring drug treatment in small animals is limited. Near-infrared fluorescence (NIRF) molecular imaging is a cheap, easy-to-use, and widely available technology for small animal studies. In this report we demonstrate, for the first time to our knowledge, that NIRF imaging can be used to monitor the loading changes of Aβs in an AD mouse model.

Significance: It has long been speculated that Alzheimer’s disease (AD) is tightly associated with oxidative stress and high concentrations of reactive oxygen species (ROS) in the brain. However, comprehensive evidence from living beings is rare. In this report, inspired by the “chemistry of glow stick,” we designed oxalate-curcumin–based imaging probes to provide evidence of high ROS concentrations in AD brains in animal studies at micro- and macrolevels. At the microlevel, our imaging method identified “active” amyloid beta plaques and cerebral amyloid angiopathy via dual-color two-photon imaging. At the macrolevel, our probe could detect relatively high ROS concentrations in AD brains using near-IR fluorescence imaging. We believe that our method will be an indispensable tool for investigating ROS in living beings.

Significance: We report a quantitative Raman microscopy method that measures the concentration of protein and lipid in cells at high spatial resolution in living and in fixed samples of tissues, allowing quantitative studies of cell size and organelle regulation both in cell culture and in tissue slices; it can be applied to problems of cell size control, intracellular crowding, and lipid metabolism in the context of cell growth, cell differentiation, cell senescence, and pathology.

Turn-on fluorescence imaging is routinely studied; however, turn-on chemiluminescence has been rarely explored for in vivo imaging. Herein, we report the design and validation of chemiluminescence probe ADLumin-1 as a turn-on probe for amyloid beta (Aβ) species. Two-photon imaging indicates that ADLumin-1 can efficiently cross the blood–brain barrier and provides excellent contrast for Aβ plaques and cerebral amyloid angiopathy. In vivo brain imaging shows that the chemiluminescence signal of ADLumin-1 from 5-month-old transgenic 5xFAD mice is 1.80-fold higher than that from the age-matched wild-type mice. Moreover, we demonstrate that it is feasible to further dually-amplify signal via chemiluminescence resonance energy transfer (DAS-CRET) using two non-conjugated smart probes (ADLumin-1 and CRANAD-3) in solutions, brain homogenates, and in vivo whole brain imaging. Our results show that DAS-CRET can provide a 2.25-fold margin between 5-month-old 5xFAD mice and wild type mice. We believe that our strategy could be extended to other aggregating-prone proteins.