Chemical and biological sensors, systems and methods based on radio frequency identification

A detection system utilizing at least one radiofrequency identification (RFID) sensor comprising:

• an RFID sensor comprising:
• a substrate;
• an antenna disposed upon said substrate;
• a sensor material disposed adjacent to at least a portion of the antenna and the sensor material being selected to be sensitive to one of chemical or biological environment;
• and
• a reader for receiving and processing signals from said RFID tag, wherein said reader is configured to measure a signal in the form of a complex impedance from said RFID tag wherein said signal comprises a plurality of frequencies and changes in the real and imaginary parts of the complex impedance;
• wherein said changes in the real and imaginary parts of the complex impedance comprise a frequency shift of the maximum of the imaginary part of the complex impedance (F1 shift), a frequency shift of the minimum of the imaginary part of the complex impedance (F2 shift), a frequency shift of the maximum of the real part of the complex impedance (Fp), and changes in magnitude of the real part of the complex impedance (Zp);
• and,
• wherein said complex impedance is related to a nature and a concentration of analyte species and is derived from multivariate analysis.