Introduction
The near infrared (NIR) dyes have been extensively used in the field of noninvasive imaging for diagnostic applications which has been gaining increasing scientific attention recently. Unlike fluorescent probes that operate in the visible and ultraviolet ranges, NIR has very low absorption and scattering by body tissues, which allows for greater penetration in living subjects. It is customary to divide the NIR range into three regions or windows, whereas the first region (NIR-I) resides roughly between 650 and 950 nm. This region is currently the most commonly used region for bioimaging due to the availability of organic and inorganic probes that emit in it. The second and third windows are collectively known as "over-1000 nm NIR" (OTN-NIR or NIR-II) and offer very high penetration to living tissues, up to several centimeters in depth.
Figure 1. NIR Fluorescence imaging of mouse.
Mechanism
Near-infrared dyes are excited by specific external energy (such as lasers high-energy rays), causing their electron orbits to transition to high-energy orbits and finally release energy to return to the ground state during the process that can produce a detectable fluorescent signal. It is worth noting that only when the fluorescent dye and the excitation light have the same frequency and have high fluorescence efficiency after absorbing the energy, the fluorescent signal can be detected by the optical device.[1]
What Can Alfa Chemistry Do?
Alfa Chemistry's technical R&D team has focused on the preparation and application of NIR dyes for many years, which has established long-term cooperative relationships with many well-known enterprises and research institutions. We have conducted research on various problems encountered by NIR fluorescence imaging, which can select the appropriate solution according to the customer's experimental purpose. The NIR fluorescence Imaging technologies we provide are as follows:
- We can provide the technology of NIR fluorescence Imaging according to customer needs in order to help researchers solve the problems.
- We also can provide the technology of instrument debugging, accuracy calibration, image analysis.
Reference
- Yeroslavsky G.; et al. Stabilization of indocyanine green dye in polymeric micelles for NIR-II fluorescence imaging and cancer treatment. Biomater. Sci., 2020, 8: 2245-2254.
