• • SVD NPs achieved a molar extinction coefficient (ε) of 3.92 × 10^4 M^-1 cm^-1, a fluorescence quantum yield (QY) of 4%, and a photothermal conversion efficiency (PCE) × ε product of 2.2 × 10^4, demonstrating a balanced radiative and nonradiative decay pathway for dual-modal imaging and therapy.
• • The acceptor planarization and donor rotation strategy enabled simultaneous enhancement of NIR emission and photothermal performance, overcoming the traditional trade-off between high QY and large ε in AIE systems, which is critical for clinical translation.
• • In vivo studies confirmed successful ablation of subcutaneous tumors via NIR fluorescence imaging-guided phototherapy, validating the therapeutic efficacy of SVD NPs in a preclinical model.
• • The molecular design provides a generalizable platform for developing high-performance AIE phototheranostic agents, with potential to improve diagnostic accuracy and treatment outcomes in oncology.