Amplified ultraviolet detection of natural DNA based on Mo_6S_(9-x)I_x nanowires

摘要

We demonstrate that Mo_6S_(9_x)I_x nanowires(MoSI NWs) can serve as an excellent signal-intensifying nanomaterial for highly sensitive and label-free detection of DNA by ultraviolet(UV) spectrophotometry.The DNA extinction at 260 nm was greatly enhanced after addition of MoSI NWs solute,and the extinction value was linear with DNA concentration in the range of 0.0289-11.68 μg/mL with the real determination limit of 28.9 ng/mL.The association of DNA with the nanowires was characterized by transmission electronmicroscopy and circular dichroic spectroscopy.The results illustrate that the UV response amplification of DNA in the presence of MoSI NWs is attributed to the greater DNA coverage on the MoSI NW surface and the conformational transformation of DNA due to interaction of DNA with MoSI NWs.MoSI NWs are a promising nano-structured material for developing ultrasensitive sensors for detection of DNA.