CRISPR‐Cas Assays for Protein Detection: Strategies and Clinical Applications

Measurement of protein biomarkers with high accuracy is critical for disease diagnostics and prognostic monitoring. However, conventional analytical platforms for protein detection suffer from insufficient sensitivity for low-abundance targets and require time-consuming, multi-step workflows. The CRISPR-Cas system is emerging as a powerful tool for protein analysis, with advantages including high programmability, excellent sensitivity, and compatibility with diverse readouts. This review presents a systematic overview of recent advances in CRISPR-based protein assays. We first summarize the design principles of aptamer-, antibody-, and enzyme-mediated systems that convert protein recognition events into CRISPR-activatable nucleic acid signals. We next examine the signal amplification and readout strategies, such as direct CRISPR activation, enzyme-mediated nucleic acid amplification, and enzyme-free DNA nanotechnology, along with colorimetric, fluorescent, or electrochemical signal outputs. We also review applications of these assays in infectious diseases, cancer, and Alzheimer's disease. Finally, we discuss challenges and perspectives for next-generation CRISPR-based protein detection platforms in clinical translation.