Abstract: A sensor element comprises a metallic nanostructure formed at edges of at least two microelectrodes on a non-electrically conductive substrate. The nanostructure is formed by depositing a solution comprising at least one metal salt and a stabilizing agent on the substrate at a detection site between the microelectrodes, and applying an AC electric field to the electrodes. The sensor elements may be used in sensing platforms such as surface-enhanced Raman scattering (SERS), surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), and in electrical-based sensing such as electrochemical sensing.

Abstract: A surface enhanced Raman spectroscopy (SERS) device, comprises a non-electrically conductive substrate, at least two microelectrodes disposed on the substrate in a spaced relationship such that a detection site is formed along edges and/or between opposing edges of the microelectrodes, and a nanoparticle structure comprising a plurality of metallic nanoparticles disposed in the detection site. Assembly of the nanoparticle structure may be directed by an electric field between the at least two microelectrodes. The SERS device is inexpensive, robust, portable, and reusable. Also described herein are methods for using and preparing the SERS devices with simple, rapid, and inexpensive fabrication techniques.