Fig. 1

Schematic diagram of HCV-RT-LAMP-AuNPs-LFB assay’s principle. (A) Schematic diagram of AuNPs-LFB principles for the interpretation of HCV-RT-LAMP outcomes. I, HCV-RT-LAMP amplification products (2.0 µl) and running buffer (100 µl) are added simultaneously on the sample pad. II, Due to capillary action, the running buffer containing HCV-RT-LAMP products move forward onto the conjugate pad and nitrocellulose (NC) membrane. The dye streptavidin-coated gold nanoparticles (streptavidin-AuNPs) are rehydrated and integrate with FAM/biotin labeled HCV-RT-LAMP products. III, The FAM/biotin-labeled HCV-RT-LAMP products are captured by anti-FAM at the test line (TL). Streptavidin-AuNPs are captured by biotin-BSA at the control line (CL). IV, Interpretation of the HCV-RT-LAMP-AuNPs-LFB assay. HCV-positive results are indicated by CL and TL bands on the AuNPs-LFB. Negative results are indicated when only the CL band appears on the AuNPs-LFB. (B) Workflow of the HCV-RT-LAMP-AuNPs-LFB assay. The workflow comprises the following closely linked steps: rapid genomic RNA extraction (step 1), RT-LAMP amplification (step 2), and AuNPs-LFB visual interpretation (step 3). The entire detection process is complete within 40 min