IR-1048

IR-1048 needs to be modified with the MZ group (nitro imidazole) to form IR-1048-MZ, which has cell activity and is suitable for in vivo or in vitro experiments.

In the in vitro enzyme response experiment, the near-infrared II (NIR II) fluorescence intensity of IR-1048-MZ (5 μg/mL; incubated with NTR for 30 min) was enhanced 106.9 times after NTR-catalyzed reduction, the photoacoustic (PA) signal intensity increased from 121 to 936, and the photothermal effect increased the solution temperature from 30.4°C to 57.6°C^[1].

Experimental methods and procedures for the in vitro assay of IR-1048-MZ^[1]:
1. Cell culture
A549 cells (human lung cancer cells) were seeded at a density of 1×10⁴ cells/well in 96-well plates and incubated overnight.
2. Probe preparation
Cells were treated with IR-1048-MZ (5-20?? μg/mL) for 2 hours under hypoxic conditions (0% O₂) or normoxic conditions (20% O₂) with 500 μM NADH as a coenzyme to mimic intracellular NTR activity.
3. Fluorescence detection
NIR II fluorescence intensity was measured using a microplate reader with an excitation wavelength of 980 nm and an emission wavelength of 1046 nm.
A calibration was performed against a standard curve of NTR concentrations (0-10 μg/mL) to quantify enzyme activity.
4. Photoacoustic (PA) imaging
The treated cells were transferred into a photoacoustic imaging chamber.
Irradiated with 880 nm laser (pulsed, 100 mJ/cm²), and the photoacoustic signals were recorded using a 3D photoacoustic tomography system.
The signal intensity was analyzed to evaluate probe activation.
5. Photothermal (PT) effect evaluation
Cells were incubated with IR-1048-MZ (5 μg/mL) for 30 min under hypoxic conditions.
Irradiated with 980 nm near-infrared laser (0.1 W/cm²) for 2 min, and the temperature change was measured using an infrared thermal imager.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only. .