Rapid and simple detection of HCV RNA: enhanced colorimetric RT-LAMP method using unmodified gold nanoparticles

Despite significant global efforts to control HCV infection, there has been no observed decline in the incidence of new infections or mortality. The asymptomatic and silently progressing nature of HCV infection delays the response to potential treatments. Hence, there is a need for rapid diagnostic techniques that enable the early detection and treatment of the disease before it advances.

In this study, we developed a rapid colorimetric analysis by integrating the optical characteristics of gold nanoparticles (AuNPs) with the field-suitable reverse transcription loop-mediated isothermal amplification (RT-LAMP). By implementing optimization steps, the disparity in color between positive and negative samples was enhanced to the point where it could be easily discerned without the use of any visual aid.

The limit of detection analysis, performed with the HCV reference sample, showed a result of 10 copies/µl. In the study with clinical samples, the method demonstrated 90% specificity and 100% sensitivity. Furthermore, the analysis of the designed primer displayed a specificity rate of 100% when tested against other pathogens. The Cohen's Kappa analysis revealed a significant association between the AuNPs-based colorimetric RT-LAMP and the one step real-time PCR results.

The findings demonstrate the applicability of the method for blood screening in correctional facilities, medical institutions, and critical situations such as natural disasters.