J-Aggregation induced NIR-II fluorescence: an aza-BODIPY luminogen for efficient phototheranostics

, TA underwent self-assembly and formed J-aggregates (TAJ NPs), which showed emission at 1020 nm. High spatial resolution and adequate signal-to-noise ratio of the TAJ NPs are demonstrated for noninvasive bioimaging of the vasculature, lymph nodes and bones of mice in the NIR-II region. Moreover, the TAJ NPs exhibited good tumor enrichment efficiency with reduced liver accumulation and significant imaging-guided phototherapy performance against lung cancer cells. Taken together, this work not only introduces a new NIR-II imaging and phototheranostic agent based on J-aggregates, but also provides insight into the development of versatile organic dyes for future clinical implementation.