G-quadruplex DNAzyme-based chemiluminescence biosensing platform based on dual signal amplification for label-free and sensitive detection of protein

Detection of ultralow concentration of specific protein plays a key role in biotechnological applications and medical diagnostics. In this study, we demonstrate an amplified chemiluminescence biosensing platform for sensitive detection of protein. The biosensing platform ingeniously combines target-catalyzed hairpin assembly and Exo III-assisted signal amplification. A catalytic G-quadruplex-hemin DNAzyme is further employed to stimulate the generation of chemiluminescence in the presence of luminol and H2O2. These designs together allow a high sensitivity for the biotarget, human α-thrombin, resulting in a detection limit of 0.92 pM, and it is much lower than previous reported studies. In addition, the proposed biosensing platform is versatile. By conjugating with various recognition units, it could be employed to sensitive detect various DNA-binding proteins and might find wide applications in biomedical fields.