Catalytic hairpin assembly-assisted dual-signal amplification platform for ultrasensitive detection of tumor markers and intelligent diagnosis of gastric cancer

Quantification of extracellular tumor markers has shown great promise for non-invasive cancer diagnosis. Combined detection of multiple tumor markers instead of a single one is valuable for accurate diagnosis. Here, we integrate CRISPR-Cas12a with DNA catalytic hairpin assembly (CHA) to doubly amplify the output signal for detecting microRNA-182 (miR-182), which is overexpressed by gastric cancer patients. Additionally, we develop a CHA system with self-replicating capacity (SRCHA) to realize dual-signal amplification for the detection of carcinoembryonic antigen (CEA), a broad-spectrum tumor marker. The proposed cascade amplification strategies enable ultrasensitive detection of miR-182 and CEA with low LODs of 0.063 fM and 4.8 pg mL, respectively. Moreover, we design a ternary "AND" logic gate using different concentrations of miR-182 and CEA as inputs, which demonstrates intelligent diagnosis of gastric cancer staging with a high accuracy of 93.3% in a clinical cohort of 30 individuals. Overall, our study expands the application of CRISPR-Cas12a in biosensing and provides a new diagnostic strategy for non-invasive liquid biopsy of gastric cancer before resorting to a traumatic tissue biopsy.