Magnetically modulated fluorescent probes in turbid media

TL;DR

This paper introduces magnetically controlled fluorescent nanoprobes (MagMOONs) that can detect specific signals in turbid media by blinking, effectively distinguishing their fluorescence from background autofluorescence, even through tissue.

Contribution

The study demonstrates the use of MagMOONs for fluorescence detection in highly scattering media, showing potential for non-invasive imaging through tissue.

Findings

MagMOON fluorescence can be detected through 9 mm of chicken tissue.

Turbid media reduce signal contrast but do not prevent detection.

MagMOON blinking enables background discrimination in autofluorescent environments.

Abstract

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.