Skip to main content
. 2019 May 1;5(6):1059–1066. doi: 10.1021/acscentsci.9b00220

Figure 2.

Figure 2

Development of Red-pHocas for detecting bone-resorbing compartments. (a) Design of Red pH-activatable fluorescent probe (Red-pHocas) for detecting the acidic region in bone tissues. (b) Chemical structures of rhodamine spirolactam-based dyes Rh-1–7. (c) pH profile of fluorescence intensity of Rh-1–3 (0.2 μM) in 0.1 M citrate-phosphate buffer at 37 °C. Excited at 535 nm. (d) Time-course absorbance of Rh-1–3 (10 μM) at maximum absorption wavelengths upon a pH jump from 8.0 to 4.0 at 37 °C. (e) Chemical structures of Red-pHocas (pH-activatable) and Red-pHocas-AL (always-ON-type). (f) pH profile of the fluorescence intensity of Red-pHocas and Red-pHocas-AL (0.2 μM) in 0.1 M citrate-phosphate buffer at 37 °C. Excited at 535 nm. (g) Time-course absorbance at 562 nm of Red-pHocas (10 μM) upon a pH jump from 8.0 to 4.0 at 37 °C. Error bars represent standard deviation (N = 3).