Inverse design of guanine-defects in carbon nanotubes for high-resolution emission tuning

Defect engineering in single-wall carbon nanotubes (CNTs) offers a powerful means of tuning their properties. However, existing strategies predominantly rely on post hoc characterization of defects, and rational approaches for the pre-design of defects remain lacking. Here, we present an inverse defect-design strategy that leverages DNA-directed, guanine-specific chemistry to introduce guanine-defects into CNTs. We assign these modifications as sp² defects, which-unlike conventional sp³ defects-largely preserve the π-conjugation of CNT lattice while enabling tunable property modulation via lattice restructuring. This approach was applied to five distinct single-chirality CNT species, yielding a chirality-dependent modification index, M(n, m), capable of predicting defect-induced property changes, even for CNTs lacking prior experimental data. Guided by this index, we achieved deterministic control over emission wavelengths with an accuracy of ±1 nm and Raman profiles within 1% deviation from predictions. These precisely engineered CNTs were further utilized for pattern switching and multilayer information encryption, highlighting the potential of precision defect design in advancing next-generation CNT-based materials.