A fluorescent probe for protein tyrosine kinase 7 detection in serum and cell imaging

Tyrosine protein kinase 7 (PTK7) is overexpressed in breast cancer, which is considered as a cancer marker for breast cancer diagnosis. Therefore, a simple fluorescent probe for PTK7 detection and cell imaging was developed. In the developed probe, Fe₃O₄ magnetic nanoparticles were used as the fluorescent separator, and the fluorescence of carbon dots were used as the detection signal. The probe was worked by control the configurations of the aptamer of PTK7, the aptamer would be open chains by recognition of PTK7, which bond with carbon dots and show fluorescent signal. Based on the remarkably high affinity and selectivity of aptamer for PTK7, the excellent fluorescence property of carbon dots and the outstanding magnetism of Fe₃O₄ magnetic nanoparticles, the developed probe showed satisfied results for PTK7 detection in serum and MCF-7 cell imaging. The probe detected PTK7 in the range of 0.2-200 ng mL^-1 with a detection limit of 0.0347 ng mL^-1, and successfully imaged the cancer cell expressed PTK7. The results indicate that the nano-fluorescent probe has great potential for clinical applications.