Fig. 2.

Spectroscopic characterization of vibrational sensing effect of SREF with Rh800. a SERF sensing with the nitrile mode of Rh800. b SREF spectra of C≡N band of Rh800 (${\overline{\nu }}_{\mathrm{C}\equiv \mathrm{N}}$) dissolved in different aprotic solvents and mixtures. c ${\overline{\nu }}_{\mathrm{C}\equiv \mathrm{N}}$ follows a linear relationship with the electric field calculated from the Onsager reaction field theory. d SREF spectra of nitrile in different DMSO–water mixtures. e Plot of ${\overline{\nu }}_{\mathrm{C}\equiv \mathrm{N}}$ in DMSO–water binary mixture against water volume ratio