Photoactive Hybrid AuNR-Pt@Ag2S Core-Satellite Nanostructures for Near-Infrared Quantitive Cell Imaging

The quantitative detection of microRNA (miR) and multimode-imaging-induced photothermal therapy in vivo have become the focus of much attention. Platinum (Pt) decorated gold nanorods (AuNR-Pt) and Ag2S core-satellite (AuNR-Pt@Ag2S) multifunctional nanostructures are fabricated to quantify intracellular miRs (miR-21), near-infrared fluorescence cell quantitative imaging, and tumor ablation in vivo. When combined with miR-21, the nanoassembly displays significant fluorescence intensity in the second window of the near-infrared region (1000-1700 nm) after 808 nm excitation. The Ag2S fluorescence intensity has a good linear relationship with the amount of intracellular miR in the range of 0.054-20.45 amol ng(RNA) (-1) and a limit of detection of 0.0082 amol ng(RNA) (-1). The nanoassembly is also used to develop multimodal bioimaging, including near-infrared, X-ray computed tomographic, and photoacoustic imaging in HeLa-tumor-bearing mice. Moreover, the tumors are completely eliminated by the high photothermal capacity of the AuNR-Pt@Ag2S assembly. This nanoassembly provides a multifunctional nanoplatform for the ultrasensitive detection of miRs and tumor diagnosis and therapy in vivo.