Electrostatically Adjustable AuNR-Mediated Thermal-Start Isothermal Nucleic Acid Amplification

Loop-mediated isothermal amplification (LAMP) holds great promise for rapid nucleic acid detection. However, its application is hindered by the notable occurrence of false positives. In this work, gold nanorod (AuNR)-mediated hot start effect, which adsorbs primers and controls the release of single-stranded DNA (ssDNA) primers at about 50 °C, was demonstrated. The AuNR-mediated LAMP reaction for detecting African horse sickness virus (AHSV) showed high selectivity against other DNA fragments, even at high magnesium concentrations. Furthermore, the assay achieves excellent sensitivity with a detection limit of 100 copies/μL. Additionally, the method displays good repeatability from 50 to 65 °C (optimal), and the coefficient of variation of Tt at the same concentration of nucleic acids is less than 5%. Our study optimizes the LAMP reaction using AuNRs, thereby reducing false positives and offering great potential for clinical diagnosis.