Mesoporous Carbon Nanospheres Featured Fluorescent Aptasensor for Multiple Diagnosis of Cancer <i>in Vitro</i> and <i>in Vivo</i>

Multiple diagnosis of cancer by a facile fluorescent sensor is extremely attractive. Herein, a Cy3-labeled ssDNA probe (P<sub>0</sub>-Cy3) was π–π stacked on the surface of oxidized mesoporous carbon nanospheres (OMCN) to construct the fluorescent “turn-on” aptasensor. Attributing to the intrinsic properties of OMCN, the OMCN-based aptasensor not only can be used to detect mucin1 protein in liquid with a wide range of 0.1–10.6 μmol/L, a low detection limit of 6.52 nmol/L, and good selectivity, but also can quantify the cancer cells in solution with the linear range of 10<sup>4</sup>–2 × 10<sup>6</sup> cells/mL and a detection limit of 8500 cells/mL. Fascinatingly, this OMCN-based aptasensor was exploited to image cancer via solid tissues such as cells, tissue sections, and <i>ex vivo</i> and <i>in vivo</i> tumors, in which the obvious distinguishability between cancer and normal tissues was clearly demonstrated. This is a robust and simple detection technique, which can well achieve the multiple diagnosis of cancer <i>in vitro</i> and <i>in vivo</i>.