Schematic illustration shows GSH-responsive probe for in vivo imaging of liver inflammation. (a) General design of liver-targeted and GSH-responsive 1H-MRI/19F-MRS/fluorescent trimodal probe (GdNPs-Gal) via coassembly of 1-Ga and 1-Gal at a mole ratio of 5/1. (b) The proposed mechanism of GdNPs-Gal for in vivo imaging of liver inflammation. Following systemic administration into mice, GdNPs-Gal can be delivered into the liver and enter liver cells through the recognition between β-Gal and ASGPR. In healthy hepatocytes, disulfide reduction and disassembly of GdNPs-Gal are initiated by the abundant endogenous GSH, leading to reduction in 1H-MRI contrast but enhanced fluorescence and 19F-MRS signals in the normal liver; in hepatitis cells, the reduced GSH levels can slow down the disulfide reduction and disassembly of GdNPs-Gal, thereby producing a strong MR contrast but low fluorescence and 19F-MRS signals in the inflammatory liver. (c) Chemical structure of DOTA-Gd and β-Gal.