Fig. 1
a The TEM image of GPRPP-Y8U@P. b The size distribution of GPRPP-Y8U@P. c The Fourier transform infrared spectroscopy (FTIR) spectra of GPRPP-Y8@P (upper) and Y8@P (low). Based on the curve of Y8@P, the characteristic peak of the GPRPP-Y8@P is about 1650.31 cm−1, which is caused by the stretching vibration of the amide bond, proving GPRPP was connected successfully. d The BCA standard curve of GPRPP in MES to calculate GPRPP loading rate. e The fluorescence spectroscopy of Y8 in DCM and GPRPP-Y8U@P in PBS. f The fluorescence emission spectroscopy of Y8 in DCM and GPRPP-Y8U@P in PBS. g The absorption of GPRPP-Y8U@P at different concentrations and the absorption coefficient was calculated at 8.64685. h Pictures of GPRPP-Y8U@P in corresponding storage media at room temperature. The storage media were DMEM and ddH2O at different pH values (pH = 5.4, 7, 8.4). i Stability of GPRPP-Y8U@P after seven days' preservation