Graphene oxide-gold nanoparticles hybrids-based surface plasmon resonance for sensitive detection of microRNA.

In this study, a simple and sensitive surface plasmon resonance (SPR) biosensor for miRNA detection was developed using graphene oxide-gold nanoparticles (GO-AuNPs) hybrids as signal amplification element. Taking advantage of the GO-AuNPs hybrids and their enhanced performance in SPR biosensors, the detection of miRNA was carried out in only two steps. Firstly, the thiolated capture DNA probe with a short complete complementary sequence was immobilized on the Au film surface to recognize the part sequence of target miRNA. Subsequently, the assistant DNA-linked GO-AuNPs hybrids were employed to bind the other section of the target. It was found that the developed SPR biosensor was able to achieve a detection limit as low as 1 fM. Moreover, the method showed excellent ability to discriminate differences among miRNA-200 family members. Notably, human miRNA from cancer cells could also be detected, and the results were in excellent agreement with the ones obtained using qRT-PCR. On the basis of these findings, we believe that this method has great potential for quantitative detection of miRNA in biomedical research and early clinical diagnostics.