Hierarchical biomarkers detection via a universal polydopamine probe catalyzed by a hexagonal star-nanostructured DNAzyme

Incompatible cross-platform detection technologies adopted for different medical scenarios has caused several problems in the clinical detection of disease biomarkers. Here, we developed a unified platform with hierarchical performance for biomarker detection. A hexagonal star-nanostructured DNAzyme was constructed. It shows excellent catalytic activity towards the deposition of polydopamine, which is capable of presenting colorimetric signals directly and is also scalable to present fluorescent and electrochemical signals by conjugating with quantum dots. This scalable detection system is validated for the detection of both nucleic acid biomarkers (miRNAs) and protein biomarkers (carcinoembryonic antigen and platelet-derived growth factor). Results show that the detection system can adapt to the current colorimetric, fluorescent and electrochemical equipment, possess the advantage of high efficiency and low-cost, and present hierarchical performance in terms of operability and sensitivity, making it possible to verify the results in a unified system and to switch the detection methods according to different scenarios.