Skip to main content
. 2022 May 13;12(5):333. doi: 10.3390/bios12050333

Figure 2.

Figure 2

(a) Chemical structures of ion pairs and polymer matrices: (HPTS)/(CTA)3, (HPTS)/(TOA)4, poly(methyl methacrylate)(PMMA), and poly(propyl methacrylate)(PPMA). The pH sensitivity of the ion pairs arises from the highlighted functional groups. (b) Emission spectra of (HPTS)/(CTA)3 in PPMA and (HPTS)/(TOA)4 in PPMA and PMMA under CO2 and N2 conditions. (c) Excitation spectra (collected at 570nm) of (HPTS)/(CTA)3 in PPMA and (HPTS)/(TOA)4 in PPMA and PMMA under CO2 and N2 conditions. (d) Moisture sensitivity of (HPTS)/(TOA)4 in PPMA and PMMA under CO2 and N2 conditions. (e) Photostability comparison of (HPTS)/(TOA)4 in PPMA and PMMA under air condition.