Construction of Mitochondria Targeted and Fret Based Ratiometric Sensing Nanoplatform for Sulfur Dioxide Accurate Detection in Vitro and in Vivo

Abstract

Sulfur dioxide (SO2) is one key molecule in organism involved in the regulation of variety physiological procedures. Aberrant SO2 leads to diseases such as cancer, neurodegeneration. So, sensitive and selective detection of SO2 is of great importance.  Based on the Förster resonance energy transfer (FRET) between green fluorescence carbon dots (GCDs) donor and amide-linked near-infrared fluorescence emissive organic small molecular dye (CDDBT) acceptor, one ratiometric fluorescent nano platform, Mito-GCDs-CDDBT for mitochondria SO2 sensing was constructed. CDDBT served as the receptor for SO2 in this FRET sensing system, presence of SO2 enhanced GCDs green fluorescence signal and quenched CDDBT near-infrared fluorescence signal due to disruption of FRET. Mito-GCDs-CDDBT exhibited capacity for sensitively detecting SO2 with a detection limit as low as 0.701 μM. Meanwhile, Mito-GCDs-CDDBT achieved fluorescence imaging for measuring the response of cellular exogenous and endogenous SO2 with good mitochondrial targeting. Moreover, Mito-GCDs-CDDBT also realized SO2 sensing in vivo including zebrafish and mice. The as prepared versatile naoplatform displayed several advantages, such as mitochondria targeting, FRET-based sensitive detection, and sensing capabilities in biological milieu. It could be potentially applied in the diagnostics of SO2 involved diseases.

Keywords: Carbon dots, FRET, Mitochondria targeted, SO2, Bioimaging