Figure 7.
PAM specificity enhancement. (a) Dichroism PAM of amyloid plaques in an APP/PS1 mouse brain section stained with Congo Red (CR), acquired with two orthogonally polarized optical irradiations P1 and P2. (b) Subtraction of P1 and P2, which eliminates the non-dichroic background and highlights the dichroic contrast of the amyloid plaques. Inset: close-up of the boxed area, showing the bipolar dichroism pattern of a representative amyloid plaque indicated by yellow arrows in (a–b). (a–b) were adapted with permission from [166]. (c) Magnetomotive PAM of magnetic nanoparticles (MNP) trapped in MNP-ink solution in a tube. R: the tube was closer to the right magnet; L: the tube was closer to the left magnet. Note that MNPs changed their positions while the nonmagnectic ink did not. The white dashed circles indicate the tube boundary. (d) Subtraction of R and L, which substantially suppresses the undesired background signals. (c–d) were adapted with permission from [168].