Abstract: Embodiments of the invention include a wireless sensor, such as an RFID tag, that includes a substrate, an antenna disposed on the substrate, and an environmentally sensitive sensor material disposed over at least a portion of said substrate. Other embodiments an RFID tag and at least one antibody coupled to the RFID tag. The RFID tag includes a substrate, circuitry disposed on the substrate, and an antenna coupled to the substrate. The at least one antibody is capable of affecting the signals emanating from the RFID tag. Further embodiments include a detection system that includes a reader. Yet other embodiments include a method for detecting specific analytes. The method includes providing an RFID tag which emanates a first signal having a first frequency, and enabling the RFID tag to emanate a second signal having a second frequency upon attraction of a specific analyte to the RFID tag.

Abstract: Disclosed herein is a method for making a nanoparticle film comprising dispersing nanoparticles in a first liquid; adding a second liquid to the first liquid to form a nanoparticle film on top of a solution comprising the first liquid, the second liquid and the nanoparticles, wherein the second liquid has a dielectric constant that is different from a dielectric constant of the first liquid; and contacting a substrate with the solution to deposit the nanoparticle film onto the contacted portion of the substrate.