NIR fluorescent probes are molecules or nanomaterials capable of emitting fluorescent signals in the NIR light region, that can combine with biomolecules or cells to enable visual detection of structure and function within an organism. Their high tissue penetration depth, low spontaneous fluorescence background, and high signal-to-noise ratio are important research tools in the field of biomedical detection and imaging.

Using Ag2S quantum dots as near-infrared biII fluorescent probe, high-resolution imaging of mouse tumor and vasculature, and further using Ag2S quantum dots as carriers to achieve targeted delivery of anticancer drugs and visualization of therapeutic effects.