Fabrication Of The High-ordered Alloy Arrays And Surface-enhanced Raman Scattering Properties

Raman spectroscopy is an efficient detection tool that can be widely used in biosensing,chemical analysis and single molecule detection.The noble metal alloy array SERS substrate is highly concerned with its high sensitivity,high reproducible and unique surface plasmon resonance characteristics.In this paper,highly ordered silicon pillar arrays has been prepared by photolithography.Then,taking silicon pillar arrays as template,obtained excellent performance noble metal alloy SERS arrays through electrochemical reaction self-assembly.The main contents of this paper are listed as follows:1.The pattern arrays have been fabricated by photolithography.Subsequently,a XeF2 dry etcher systems is adopt to isotropically etch the silicon for less than one minute,and then the high ordered,good hydrophobic silicon pillar arrays are obtained.2.The Au/Ag alloy arrays were prepared through electrochemical reduction self-assembly with a silicon pillar substrates as a template.During this process,in order to control the morphology of the noble metal alloy,the nucleation and growth were adjusted via changing the applied voltage and reaction time,and the proportion of each atom in the alloy can also be controlled by regulating the proportion of ion concentration in the electrolyte solution.When the applied voltage was 24 V and the electrolysis time was 25 min,a flower-like Au/Ag alloy arrays with a gold content of 12 at.%was successfully prepared and show the best SERS performance.Furthmore,using the above alloy arrays,R6G with the concentration of 10-12 M could be detected.The results show that the alloy arrays of the flower-like structure has a large volume-to-surface ratio,high roughness and more Raman "hot spots".At the same time,a small amount of Au(12 at.%)which can lead to a charge separation and favor the probe molecules adsorption to the silver domains.3.The Au/Cu alloy arrays were prepared through electrochemical reduction self-assembly by using a silicon pillar substrates as a template.The highly ordered flower-like Au/Cu alloy arrays with massive nanogap were successfully prepared by adjusting the applied voltage,reaction time and the molar ratio of Au3+ and Cu2+ in the electrolyte.The excellent SERS can be observed under a amount of Au(44 at.%)in the Au/Cu alloy.By using these flower-like Au/Cu alloy arrays,the R6G with the concentration of as low as 10-14M can be detected.In this paper,a very promising method with wide application has been proposed,by which the high sensitive and reproducible SERS substrate can be prepared flexibly at room temperature.