The folder “Figure 2” contains (2a) normalised UV/Vis absorption (20 μM in THF) and emission (20 μM in 10:90 by vol% THF/H2O) spectra data of DMTPS and DMTPS-Sil. The emission spectra were recorded at front face configuration, with excitation wavelength (λex) of 370 and 390 used for DMTPS and DMTPS-Sil, respectively. Emission spectra data of (2b) DMTPS (λex = 370 nm) and (2c) DMTPS-Sil (λex = 390 nm) measured in pure THF and 10:90 (v/v) THF/H2O mixture. The folder “Figure 3” contains the raw data for the normalised mean intensity extracted from the histograms of confocal microscopy images recorded throughout the gelation process using lase excitation of 405 nm (for DMTPS-d-UPTES and DMTPS-Sil-d-UPTES mixtures) and 488 nm (for LR305-d-UPTES mixture). The folder “Figure 4” contains the normalised emission spectra data of (4c) DMTPS (λex = 370 nm) and (4d) DMTPS-Sil (λex = 390 nm) in 10:90 (v/v) THF/H2O solvent mixture and dU(600) at concentrations of 0.014mM, 0.14 mM and 1.4 mM. The UV/Vis/NIR transmittance spectra data of (4e) DMTPS-dU(600)-x and (4f) DMTPS-Sil-dU(600)-x sample series. The folder “Figure 5” contains the data for TCSPC instrument response function, emission decay curves and the corresponding fits and residuals of (5a) DMTPS-Sil-dU(600)-x and (5b) DMTPS-dU(600)-x sample series upon excitation at 375 nm and detection of the emission decay curves at 600 nm. The pre-exponential factor, αi, associated with the emission decay of (4c) DMTPS-Sil-dU(600)-x and (4d) DMTPS-dU(600)-x sample series. The folder “Figure 6” contains the data for TCSPC instrument response function, emission decay curves and the corresponding fits and residuals of DMTPS-Sil-dU(600)-x sample series upon excitation at 375 nm and detection of the emission decay curves at 390 nm. The folder “Figure S5” contains the FTIR spectra data of the precursor Jeffamine ED-600, ICPTES and their product d-UPTES. The folder “Figure S9” contains data for the normalised emission spectra of the filtered acetone solution used to immerse (S9b) DMTPS-dU(600) and dU(600) (λex = 370 nm) and (S9d) DMTPS-Sil-dU(600) and dU(600) (λex = 390 nm). The folder “Figure S10” contains the data for the normalised emission spectra of acetone as a function of excitation wavelength under ambient conditions. The folder “Figure S11” contains the data for TCSPC instrument response function, emission decay curves and the corresponding fits and residuals of (S11a) DMTPS-Sil and (S11b) DMTPS in THF and 10:90 (v/v) THF/H2O solvent mixture upon excitation at 375 nm and detection of the emission decay curves at 600 nm. The folder “Figure S12” contains the data for TCSPC instrument response function, emission decay curves and the corresponding fits and residuals of DMTPS-Sil-dU(600)-x sample series upon excitation at 450 nm and detection of the emission decay curves at 620 nm. The folder “Figure S13” contains the data for the normalised excitation and emission spectra of dU(600) and the normalised absorption and emission spectra of DMTPS-Sil measured in 10:90 (v/v) THF:H2O solvent mixture at a concentration of 20 μM.