Table 1.
Compositions of sensing hydrogel films of F1–F9 and their sensitivity.
| Films | HEMA a | AM a | PEGDMA in the Total Weight of HEMA and AM | Film-Forming | Sensitivity to DO b (I0/I100) | Sensitivity to Ph c (IpH9.0/IpH3.0) |
|---|---|---|---|---|---|---|
| F1 | 100 | 0 | 10 | yes | 5.73 | 17.3 |
| F2 | 95 | 5 | 10 | yes | 5.95 | 18.0 |
| F3 | 85 | 15 | 10 | yes | 5.83 | 21.4 |
| F4 | 75 | 25 | 10 | yes | 1.54 | 11.3 |
| F5 | 65 | 35 | 10 | no | - | - |
| F6 | 85 | 15 | 2.5 | no | - | - |
| F7 | 85 | 15 | 5.0 | yes | 4.28 | 17.6 |
| F8 | 85 | 15 | 15 | yes | 3.39 | 22.3 |
| F9 | 85 | 15 | 20 | yes | 2.31 | 24.5 |
a Weight ratios of HEMA/AM in the gel films. b Fluorescence intensity ratios between those with 100% nitrogen and with 100% of oxygen. I0 is the emission intensity at 645 nm under deoxygenated condition; I100 is the emission intensity under oxygenated condition. c Fluorescence intensity ratios between those at pH 9.0 BR buffer and at pH 3.0 BR buffer. IpH9 is the emission intensity of 525 nm at pH 9; IpH3 is the emission intensity of 525 nm at pH 3.