Although CRISPR-Cas12a [clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 12a] combining pre-amplification technology has the advantage of high sensitivity in biosensing, its generality and specificity are insufficient, which greatly restrains its application range. Here, we discovered a new targeting substrate for LbaCas12a (Lachnospiraceae bacterium Cas12a), namely double-stranded DNA (dsDNA) with a sticky-end region (PAM⁻SE⁺ dsDNA). We discovered that CRISPR-Cas12a had special enzymatic properties for this substrate DNA, including the ability to recognize and cleave it without needing a protospacer adjacent motif (PAM) sequence and a high sensitivity to single-base mismatches in that substrate. Further mechanism studies revealed that guide RNA (gRNA) formed a triple-stranded flap structure with the substrate dsDNA. We also discovered the property of low-temperature activation of CRISPR-Cas12a and, by coupling with the unique DNA hybridization kinetics at low temperature, we constructed a complete workflow for low-abundance point mutation detection in real samples, which was fast, convenient and free of single-stranded DNA (ssDNA) transformation. The detection limits were 0.005–0.01% for synthesized strands and 0.01–0.05% for plasmid genomic DNA, and the mutation abundances provided by our system for 28 clinical samples were in accordance with next-generation sequencing results. We believe that our work not only reveals novel information about the target recognition mechanism of the CRISPR-Cas12a system, but also greatly broadens its application scenarios.

Detecting small molecules is pivotal across fields like clinical diagnostics, environmental monitoring, and food safety. The CRISPR-Cas12a system, known for its simplicity and sensitivity, offers a promising basis for small molecule detection. However, current CRISPR-based detection methods face challenges, including complex design requirements, high background noise, and limited adaptability to different targets. In our study, we introduce the SBS-Cas system, leveraging a split crRNA mode to induce spatial hindrance on the scaffold strand through molecular binding. This approach prevents the assembly with Cas12a, effectively masking its trans-cleavage activity. By introducing small molecules that competitively bind to the macromolecule, we eliminate this spatial hindrance, activating Cas12a. Our results demonstrate high sensitivity, versatility, and adaptability in small molecule detection across multiple reactions, with successful intracellular imaging and responsive fluctuations in complex environments underscoring the system’s robustness. This innovative CRISPR-Cas12a-based approach establishes a low-background, highly sensitive platform for small molecule detection. SBS-Cas promises not only to enhance tools for clinical, environmental, and food safety applications but also to advance CRISPR research, providing insights and expanding possibilities in molecular detection science.

Selenium nanoparticles (SeNPs) with mitochondria targeting ability can significantly enhance the reactive oxygen species (ROS) induced cell death in cancer cells, while remaining less toxic in healthy cells.

Dendrimers are a family of nano‐sized three‐dimensional polymers with unique dendritic branching structures and compact spherical geometries. In recent years, dendrimers have made a series of breakthroughs in the biomedical field. In this review, we introduce the synthesis principles, modification methods, and new materials designed based on dendrimers; discuss the importance of cytotoxicity of dendrimers for applications; and elaborate on their applications in the field of molecular assembly and cancer diagnosis and treatment. We speculate that in the near future, more new materials based on dendrimers will be applied in the biomedical field.