Performance Evaluation of Surface-Enhanced Raman Scattering–Polymerase Chain Reaction Sensors for Future Use in Sensitive Genetic Assays
Yixuan Wu, Namhyun Choi, Hao Chen, Hajun Dang, Lingxin Chen, Jaebum Choo
Abstract
We report a surface-enhanced Raman scattering (SERS)-based polymerase chain reaction (PCR) assay platform for the sensitive and rapid detection of a DNA marker (pagA) of Bacillus anthracis. Real-time quantitative PCR (RT-qPCR) has been recently considered a gold standard for the quantitative evaluation of a target gene, but it still suffers from the problem of a long thermocycling time. To address this issue, we developed a conceptually new SERS–PCR platform and evaluated its performance by sequentially measuring the Raman signals of B. anthracis DNA after the completion of different thermocycling numbers. According to our experimental data, SERS–PCR has lower limits of detection (LODs) than RT-qPCR under the small cycle number of 20. Particularly, it was impossible to detect a target DNA amplicon using RT-qPCR before the number of cycles reached 15, but SERS–PCR enabled DNA detection after only five cycles with an LOD value of 960 pM. In addition, the dynamic range for SERS–PCR (0.1–1000 pM) is wider than that for RT-qPCR (150–1000 pM) under the same condition. We believe that this SERS–PCR technique has a strong potential to be a powerful tool for the rapid and sensitive diagnosis of infectious diseases in the near future.