Sensitive Detection of Nucleic Acids with Rolling Circle Amplification and Surface-Enhanced Raman Scattering Spectroscopy

摘要

Detection of specific DNA sequences is important tonmolecular biology research and clinical diagnostics. Tonimprove the sensitivity of surface-enhanced Raman scatteringnspectroscopy (SERS), a variety of signal amplificationnmethods has been developed, including Ramanactive-ndye, polymerase chain reaction (PCR) technology,nmolecular beacon, SERS-active substrates, and SERS-tag.nHowever, the combination of rolling circle amplificationn(RCA) with SERS for nucleic acid detection has not beennreported. Herein, we describe a new approach for nucleicnacid detection by the combination of RCA reaction withnSERS. Because of the binding of abundance repeatednsequences of RCA products with gold nanoparticle (AunNP) and Rox-modified detection probes, SERS signal isnsignificantly amplified and the detection limit of 10.0 pMnmight be achieved. The sensitivity of RCA-based SERS hasnincreased by as much as 3 orders of magnitude asncompared to PCR-based SERS and is also comparablenwith or even exceeds that of both RCA-based electrochemicalnand RCA-based fluorescent methods. This RCA-basednSERS might discriminate perfect matched target DNAnfrom 1-base mismatched DNA with high selectivity. Thenhigh sensitivity and selectivity of RCA-based SERS makesnit a potential tool for early diagnosis of gene-relatedndisease and also offers a great promise for multiplexednassays with DNA microarrays.