As a new type of nano-catalytic materials, silver-platinum nanoclusters have attracted more and more attention in the fields of biosensors and catalysis. A novel colorimetric method for CEA was developed based on the catalytic activity of peroxidase of DNA-Ag/Pt nanoclusters (NCs) and rolling circle amplification (RCA) and CRISPR/Cas12a. In this paper, DNA-Ag/Pt NCs can catalyze H₂O₂ to oxidize 3,3,5′,5′-tetramethyl benzidine (TMB) to form blue substance ox-TMB. Target CEA can specifically bind to the aptamer and releases the primer chain, which initiates the RCA reaction and activates the trans-cleavage activity of the Cas12a/crRNA, and the signal probe DNA-Ag/Pt NCs is hydrolyzed immediately, thus causing signal changes in the system. Due to signal amplification by combining RCA with CRISPR/Cas 12a system, the visual sensor has a high sensitivity for CEA with a linear range of 2.5 pg/mL to 2.0 ng/mL and a detection limit of 0.94 pg/mL (S/N = 3). Furthermore, the sensor has the advantages of good specificity, satisfactory results for the detection of actual samples and simple operation, indicating that this method has a potential application prospect in clinical detection.

银铂纳米团簇作为一种新型的纳米催化材料，在生物传感器和催化领域越来越受到关注。基于 DNA-Ag/Pt 纳米簇 (NCs) 过氧化物酶的催化活性和滚环扩增 (RCA) 和 CRISPR/Cas12a 的催化活性，开发了一种新的 CEA 比色方法。在本文中，DNA-Ag/Pt NCs 可以催化 H ₂ O ₂将3,3,5',5'-四甲基联苯胺(TMB)氧化成蓝色物质ox-TMB。靶CEA可特异性结合适体并释放引物链，启动RCA反应并激活Cas12a/crRNA的反式切割活性，信号探针DNA-Ag/Pt NCs立即水解，从而引起信号变化在系统中。由于通过将RCA与CRISPR/Cas 12a系统相结合进行信号放大，视觉传感器对CEA具有高灵敏度，线性范围为2.5 pg/mL至2.0 ng/mL，检测限为0.94 pg/mL（S/N = 3)。此外，该传感器具有特异性好、对实际样品检测结果满意、操作简单等优点，表明该方法在临床检测中具有潜在的应用前景。