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.

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.

Abstract: An electrokinetics-assisted sensor for sensing a target material. The sensor may include a microstructure deflectable in response to added mass on its body. The sensor may also include one or more features on or near the microstructure designed to generate an electric field giving rise to one or more electrokinetic effects to drive material towards the microstructure, when an electrical signal is applied to the feature(s). Presence of the target material on the body of the microstructure may cause a response in the microstructure, including a detectable change in deflection of the microstructure.

Abstract: A filter has a conduit having an opening for flow of fluid into the conduit, a pump for pumping fluid into the conduit through the opening, electrodes spaced apart from each other across the opening such that fluid flowing through the opening passes between the electrodes; and an AC electrical source for the electrodes, the source of AC electrical energy having a frequency and voltage such that an electric field created by the AC electrical energy in the area around the electrodes imposes a negative dielectrophoretic force on target particles carried by the fluid, the negative dielectrophoretic force being opposed to the direction of fluid flow through the opening and having sufficient strength to prevent the target particles from passing between the electrodes into the conduit. The filter is mounted in a bioreactor for filtering viable cells and retaining them in culture medium.