Fabrication of Highly Branched Silver Dendritic Nanostructures for Ultrasensitive Molecule Detection

Metal nanoparticles with highly branched morphologies are extremely advantageous owing to their unique structural properties and applications in sensing, imaging, and catalysis. In this work, anisotropically branched metal nanostructures are fabricated via a simple and one-step chemical reduction method. The fabricated nanostructures display highly branched dendritic morphology and exhibit a broad plasmonic response from UV to MR region of the electromagnetic (EM) spectrum. The fabricated silver nanostructures were utilized for the Surface Enhanced Raman Spectroscopy (SERS) based detection of Rhodamine B dye molecules with a Raman intensity enhancement factor of the order of similar to 10(9). The extreme localization of EM fields at the sharp tips and within the nanoscale inter-branch gaps results in an ultralow limit of detection similar to 10(-18) M concentration of the analyte with high signal reproducibility. The present methodology provides a reliable method for the preparation of silver nanodendrites based SERS substrates and offers great potential for the ultrasensitive detection of analyte molecules.