Pressure and Fluorescence Dual Signal Readout CuO-NiO/C Heterojunction Nanofibers-Based Nanoplatform for Imaging and Detection of Target Cancer Cells in Blood

The development of multifunctional nanoplatform, which integrates biosensing and imaging diagnosis, for accurate identification of cancer cells in blood or other bodily fluids is critical for early cancer diagnosis and treatment. Herein, by using a facile single spinneret electrospinning technique followed by thermal treatment, CuO-NiO/C heterojunction nanofiber was synthesized. The resultant CuO-NiO/C nanofibers exhibited excellent catalytic activity toward ammonia borane (AB) hydrolysis, producing a marked pressure increase in a closed reaction vessel. Moreover, the resultant nanofibers showed highly efficient catalytic activity for reduction of rhodamine 6G (Rh6G, fluorescent molecule), accompanied by the fluorescence quenching. On the basis of these findings, a novel sensing platform utilizing folic-acid (FA) conjugated CuO-NiO/C nanofibers as an artificial enzyme and recognition element for fluorescence imaging and pressure-based (pressure meter) detection of folate receptor (FR)-positive cancer cells was developed. The detection limit is as low as 50 cells/mL. What's more, the clinical applicability of the sensor was also proven to be suitable for the sensing cancer cells in whole blood. The most important advantage of the synthesized nanofibers based-probe is the combination of pressure meter and fluorescence imaging to specifically see and sensitively count the cancer cells, paving a new way in early liver cancer diagnosis.