Abstract: The present disclosure provides systems and methods for separating one or more analytes within a fluid mixture, and characterizing and/or detecting properties associated with the one or more analytes. In some embodiments, the systems provided herein contain a dielectrophoresis device, such as a gradient insulator-based dielectrophoresis device (g-iDEP). The present disclosure provides systems and methods for separating and characterizing analytes using particle or nanoparticle tracking analysis (NTA). NTA offers various advantages because, particle size and concentration can be calculated in real time, allowing label-free and simultaneous characterization and separation of samples with mixed and unknown analytes.

Abstract: The invention provides nanoparticles comprising one or more redox-active species, methods of making such nanoparticles, and methods for using such nanoparticles, for example, as diagnostic agents for the detection of various analytes.

Abstract: The present invention provides a new class of Raman-active reagents for use in biological and other applications, as well as methods and kits for their use and manufacture. Each reagent includes a Raman-active reporter molecule, a binding molecule, and a surface enhancing particle capable of causing surface enhanced Raman scattering (SERS). The Raman-active reporter molecule and the binding molecule are affixed to the particle to give both a strong SERS signal and to provide biological functionality, i.e. antigen or drug recognition. The Raman-active reagents can function as an alternative to fluorescence-labeled reagents, with advantages in detection including signal stability, sensitivity, and the ability to simultaneously detect several biological materials. The Raman-active reagents also have a wide range of applications, especially in clinical fields (e.g., immunoassays, imaging, and drug screening).