Fast fabrication of homogeneous Ag nanostructures on dual-acid doped polyaniline for SERS applications

We demonstrate a dual-acid doping technique for PANI membranes, which enables fast fabrication of homogeneous Ag nanostructures as SERS-active platforms for chemical detection. Ascorbic acid, an intrinsic reducing agent, can accelerate the Ag growth, and succinic acid plays the role of controlling the morphology of the Ag nanostructures. When ascorbic acid is used alone, bulk Ag particles are obtained, which show relatively poor SERS sensitivity (10(-5) M) towards the target analyte, methylene blue (MB). Homogeneous Ag nanostructures assembled by nanosheets can be fabricated on dual-acid doped PANI membranes within 2 min. These Ag nanostructures are extremely sensitive towards both target molecules, Rhodamine B (RhB) and MB, with a detection sensitivity of 10(-10) M. The as-fabricated SERS platforms can also be applied for semi-quantitative determination of the carcinogenic RhB in juice. We believe the as-fabricated highly sensitive SERS platforms can be promising in the trace detection of chemical and biological molecules.