The noncovalent interaction between carbon nanotubes and molecular groups leads to hybrid systems with low stability and poorly defined structure in terms of the density of functional groups, their relative positions and orientation. Since these factors are affected by microenvironmental parameters, studying the charge transfer of such dynamic systems is challenging. Covalent attachment of molecular probes, on the other hand, disturb the π-conjugated integrity of carbon nanotubes and suppress their light emission1,2. In 2017, we explored a nondestructive covalent functionalization (NCF) that opens up new avenues to overcome the aforementioned challenges3. NCF is an effective strategy for the preparation of stable carbon nanotube hybrids with defined functionality and preserved photoluminescence property4. In this work, we have used NCF for the mechanistic study of covalent bond-mediated charge transfer between molecular probes and carbon nanotubes by manipulating the structure of the probes. Different molecular probes with the same backbone but different functionality were synthesized by reaction between aniline derivatives and cyanuric chloride (Figure 1a). The conjugation of the molecular probes to the surface of carbon nanotubes by nitrene [2+1] cycloaddition reaction resulted in hybrid systems with the preserved physicochemical properties. π conjugated system of carbon nanotubes was integrated outwards into the backbone of molecular probes upon opening the aziridine ring in the bridge position and resulted in charge transfer between these two components (Figure 1b). Due to the same chemical backbone but different number of electron donating groups, variation in the optical properties of carbon nanotubes was assigned to the contribution of these groups in doping through which a mechanism for the covalent bond-mediated charge transfer was proposed. As a proof of concept, we have demonstrated a new way to forward the π conjugated system of carbon nanotubes outwards into other (macro)molecules which results in new systems with the unique optoelectronic properties. References Cognet, L. et al. Science 2007, 316, 1465.Piao, Y. et al. Chem. 2013, 5, 840.Setaro et al. Nat Commun. 2017, 8, 14281.Godin et al. Science Advances, 2019, 5, eaax116. Figure 1