Papers of the Week

The surface-enhanced Raman spectroscopy (SERS) has attracted much attention due to the powerful capability of quantificational analysis. Nowadays, most of the enhancement effect by SERS substrate is provided by the 'hot spots' occupying relatively small space. When the amount of analyte is too low, it is difficult to ensure that all the probe molecules can be placed into the 'hot spots', which is a headache in SERS quatification. In order to solve this problem, we have developed a structure of CuO nanowires/Ag nanoparticles with wettability capacity gradient, which can aggregate molecules in water and oil simultaneously under two different mechanisms of action. The limit of detection and enhancement factor of this structure are estimated as 10-15 M and 1.55×1011 respectively (for rhodamine 6G, R6G). Moreover, in the mimic sewage detection, it successfully realizes the spontaneous separation and aggregation of R6G molecules in aqueous solution and thiuram molecules in toluene, so as to achieve a high-effective and accurate Raman detection.