(2.5 µM and 5 µM) indicated similar optical behaviour in the presence of higher concentration of MQ-CN-BTZ (Fig. ). Given that the cellualr systems contain very high concentration of NADH in the range of 119 to 217 µM, the systematic photophysical studies unveiled that, in fact, MQ-CN-BTZ can be used as dual emissive probe with one emission band close to NIR-I window in the presence of NADH. Hence, this probe can be used as dual channel imaging probe for cellular studies. During the verge of completion of our studies, two elegant reports surfaced in the literatiure where the same probe has been used for studying NADH interaction. While Wang et al. used this probe as a control while developing probe for two photon imaging of NADH level in the brain cells and revealed the metabolic abberations due to dysfunctionsing of mitochondria in Alzimer's disease, Magesh et al. used it as green-emissive probe for studying the changes in the NADH level in normoxia and hypoxia condition as well as for in vivo imaging of NADH level in living organisms. As noted, the dual emissive nature particularly the far-red emission has not been envisioned yet.