Enzyme-free and label-free fluorescence sensor for the detection of liver cancer related short gene

Non-invasive early diagnosis of liver cancer is the most effective way to improve the survival rate. In this paper, we developed a label-free and enzyme-free fluorescent biosensor based on target recycling and Thioflavin T (ThT) induced G-quadruplex formation for MXR7 (liver cancer related short gene) detection in human serum. The proposed sensor can detect the target DNA in the concentration range of 0-350 fM with the detection limit as low as 10 fM. Due to the outstanding structural selectivity of ThT for G-quadruplex, this sensor possesses better discrimination ability and higher sensitivity. Furthermore, this enzyme-free and label-free fluorescence sensor has demonstrated to be capable of detecting target DNA in human serum samples because of its high selectivity and sensitivity. The mechanism employed in this study represents a promising path toward directing liver cancer detection in human serum. In addition, this strategy may be extended to detect other cancer related genes by choosing a rational DNA probe according to different sequences of targets.