Recent advances in optical imaging of biomarkers in vivo

The rapid development of nanotechnology and optical imaging techniques provide the opportunity for visualizable monitoring the occurrence and progression of cancers with high efficiency and accuracy. Ideal platforms for sensing target analytes in vivo are characterized with good stability, biocompatibility, long-term circulation time and specific-cancer-targeting and tumor accumulation ability. By taking advantage of the versatile imaging modalities and intelligent nanoprobes, a variety of optical imaging strategies have been designed and constructed for sensitive and real-time imaging cancer biomarkers or tumor tissue in vivo. This review declares the design and fabrication of nanomaterial-based optical imaging platform and their applications in sensing and visualizing cellular cancer biomarkers and tumor microenvironments-related features in vivo. Special focus is to reveal the progresses of three optical modalities including fluorescence, photoacoustic imaging and surface enhanced Raman scattering for biomarkers imaging in vivo. We also outline the significant challenges and prospective of nanomaterial-based optical imaging towards cancer diagnosis and personalized medicine.