The pH-responsive PEGylated nanogels composed of the cross-linked poly [2-(N,N-diethylamino)ethyl methacrylate]-copoly(2,2,2-trifluoroethyl methacrylate) gel core showed a remarkable on-off regulation of F-19 magnetic resonance signal intensity (7, values) as well as signal-to-noise ratios in response to extracellular pH 6.5 Of tumor environment under F-19 magnetic resonance spectroscopic imaging (MRS/I), demonstrating the utility of the PEGylated nanogels as solid tumor-specific F-19 MRI/S nanoprobes.