One-Pot Ligation-Recombinase Polymerase Amplification-Clustered Regularly Interspaced Short Palindromic Repeats/Cas12a-Powered Trimode Lateral Flow Assay for Sensitive MicroRNA Detection

Sensitive detection of microRNAs (miRNAs) holds significant importance for the early diagnosis of cancer. Since current sensitive nucleic acid detection methods like recombinase polymerase amplification-clustered regularly interspaced short palindromic repeats (RPA-CRISPR)/Cas12a are not suitable for detecting short-stranded miRNAs, we introduced a T4 ligase-based ligation process to the RPA-CRISPR/Cas12a system and developed a novel miRNA detection method termed ligation-RPA-CRISPR/Cas12a (LRCC). This assay utilizes a glycerol-enhanced one-pot reaction strategy combined with a lateral flow assay (LFA) to streamline the operation, minimize aerosol contamination, and improve point-of-care testing performance. Kinetic studies have shown that the catalytic efficiency of the glycerol-enhanced one-pot reaction is 3.11 and 2.09 times higher than that of the direct one-pot and stepwise methods, respectively. By synthesizing "three-in-one" Au-Pt nanostars (Au@Pt NSs) as probes and stabilizing them via "click" chemistry modification, this work enabled a trimode detection approach (colorimetric, photothermal, and surface-enhanced Raman spectroscopy (SERS)) with improved accuracy. In the experiment, tetrahedron DNAs were immobilized on the test line of the strip to enhance the capture efficiency of probes, thereby improving the detection sensitivity. The entire detection process was completed in 70 min with detection limits of 23.6 fM for colorimetric (C-LFA), 2.19 fM for photothermal (P-LFA), and 72.29 aM for SERS (S-LFA). The results demonstrate the strong practical applicability of the LRCC strategy, which plays a crucial role in miRNA-based early disease diagnosis.