CRISPR-Cas12a powered multifunctional DNA nanodumbbell lock biosensor for multiple molecular detection

•A CRISPR-powered multifunctional detection biosensor was developed.•Three DNA nanodumbbell lock structures were used for multiple molecular detection.•Early-stage prostate cancer patients could be distinguished from healthy people.•The DNA nanodumbbell locks were able to assembled in advance, allowing its application even in resource limited settings. Detection of multiple biomarkers for accurate diagnosis of disease is highly desirable but remains challenging. Here, we developed a versatile diagnostic biosensor (SMARTLOCK) through the unique combination of DNA tetrahedron, nonlinear HCR and CRISPR-Cas12a system for simultaneous detection of multiple nucleic acids, small molecules, proteins and different types of combinations. Two DNA tetrahedrons are assembled into a functional dumbbell lock, which was unlocked by the target molecules, thereby triggering a two-stage signal amplification of nonlinear HCR and CRISPR-Cas12a to generate powerful fluorescence signals. The capability of multi-target simultaneous detection of SMARTLOCK is demonstrated in the detection of miR-141, miR-375, miR-21, ATP, cortisol, insulin and their combinations. SMARTLOCK could selectively (specificity = 93.3%) and sensitively (sensitivity = 90%) distinguish early-stage prostate cancer (PCa) patients (n = 10) from healthy donors (n = 30). Measurement of two PCa-related RNAs (miR-141 and miR-375) shows the potential of SMARTLOCK to be a highly accurate and low-cost tool for the screening, diagnosis and prognosis of various diseases.