Ultrasensitive Detection of Nucleic Acid and Protein at Ambient Temperature by Using an Engineered CRISPR-Cas12a-Based Digital Assay
Y. Cheng, Wenlong Guo, Yunzhu Wan, Shengli Li, Jianhua Zhou, Jiasi Wang
Abstract
The development of sensitive and convenient molecular detection technologies is crucial for early disease diagnosis and precision medicine. The CRISPR-Cas12a system has garnered significant attention due to its efficient molecular detection capabilities. However, most methods were performed at 37 °C or higher, which require a temperature control system and limit their applicability in point-of-care (POC) settings. In this study, we demonstrate that LbCpf1-Ultra, an engineered CRISPR-Cas12a, exhibits robust trans-cleavage activity at room temperature. Leveraging this finding, we developed a versatile digital CRISPR platform capable of ultrasensitive detection of viral DNA and proteins at ambient temperature, achieving a limit of detection (LOD) of 11.9 copies/μL for DNA and 5 fM for proteins. To further enhance its usability in POC environments, we integrated this platform with a smartphone-based fluorescence imaging device, enabling low-cost and on-site detection of nucleic acids and proteins without the need for external equipment. Clinical validation showcases its potential for reliable diagnostics. This platform provides a new direction for future CRISPR-based molecular diagnostics and holds promise for clinical diagnosis and precision medicine.