# Two-dimensional NIR-II AIE nanotheranostic probes with ultralarge Stokes shifts for surgical navigation and ablation of glioma

## TL;DR

A new two-dimensional NIR-II probe with a large Stokes shift helps in accurately guiding brain tumor surgery and subsequent treatment.

## Contribution

A novel tetracyanoquinodimethane-derived NIR probe (TNQ2) with a 445-nm Stokes shift and aggregation-enhanced emission is developed.

## Key findings

- TNQ2 self-assembles into sub-160 nm two-dimensional J-aggregates with red-shift absorption and aggregation-enhanced emission.
- The probe enables high-sensitivity NIR-II fluorescence imaging-guided glioma resection and phototherapy.
- The strategy establishes a new paradigm for developing advanced NIR phototheranostics for brain diseases.

## Abstract

Near-infrared (NIR) fluorescence probes featuring ultralarge Stokes shifts and efficient aggregate-state luminescence are highly desirable for bioimaging yet remain scarce due to formidable synthetic challenges and intricate photophysical modulation. We report a facile one-step click reaction to synthesize a tetracyanoquinodimethane-derived NIR probe (TNQ2) that overcomes the long-standing nonfluorescence limitation while achieving an unprecedented 445-nanometer Stokes shift. TNQ2 self-assembles into the smallest-sized two-dimensional J-aggregates (sub-160 nanometers) with a red-shift absorption from 545 to 725 nanometers and aggregation-enhanced emission around 1000 nanometers. The radiative/nonradiative modulation balances the fluorescence/photothermal/photodynamic effect to support high-sensitivity NIR-II fluorescence imaging-guided precise glioma resection and postoperative phototherapy to substantially extend survival in orthotopic glioma models. Our molecule/nanoengineering strategy establishes a transformative paradigm for developing advanced NIR phototheranostics for brain diseases.

A 2D NIR-II AIE probe enables precise glioma surgery and postoperative phototherapy via an ultralarge Stokes shift.