Magnetically modulated fluorescent probes in turbid media
Magnetically modulated optical nanoprobes (MagMOONs) were used to detect and distinguish probe fluorescence from autofluorescent backgrounds in turbid media. MagMOONs are micro/nano-sized particles with magnetically controlled orientation and orientation-dependent fluorescence. These probes blink when they rotate in response to rotating external magnetic fields. This blinking signal can be separated from backgrounds enabling spectrochemical sensing in media with strong autofluorescence. We explore the effect of scattering on MagMOON fluorescence. Turbid media reduce the modulated MagMOON signal due to a combination of attenuation of fluorescence signal and reduction in contrast between "On" and "Off" states. The blinking MagMOON fluorescence spectrum can be detected in turbid non-dairy creamer solution with extinction 2.0, and through 9 mm of chicken breast tissue, suggesting that whole mouse imaging is feasible by using this strategy.