A Novel Photosensitive Nanoprobe Combined with Crispr/Cas12a for Dual Signal Amplification Detection of Angptl2

Abstract

The detection of specific protein biomarkers holds significant potential for the early diagnosis of colorectal cancer (CRC). However, the accurate quantification of low-abundance proteins in serum presents a major challenge due to factors such as limited sensitivity, high false-positive rates, and the complexity of the required methodologies. In this work, we established a universal CRISPR/Cas biosensing platform by integrating novel photosensitive nanoprobes (DA/PL@Cu NPs) and CRISPR/Cas12 system (DPC-Cas) for the highly sensitive and specific detection of angiopoietin-like protein 2 (ANGPTL2). The DA/PL@Cu NPs serve as a critical component in the transduction of protein recognition information into nucleic acid amplification events to produce Cas12a activators. In the DPC-Cas biosensor, by integrating the dual-signal amplification of DA/PL@Cu NPs -assisted signal amplification and Cas12a self-signal amplification, ultralow abundance of target molecules can arouse numerous concatemers to activate Cas12a trans-cleavage activity to release intense fluorescence, allowing the ultrasensitive detection of as low as 50.00 pg/mL ANGPTL2. The proposed DPC-Cas biosensor successfully detected ANGPTL2 in serum, demonstrating significant potential for the early diagnosis of CRC.

Keywords: CRISPR/Cas12a, Novel photosensitive nanoprobes, Signal amplification, Early diagnosis