Abstract: A method for detecting specific associations between a tethered molecule and an untethered target molecule. The method comprises (1) selecting a tethered molecule; (2) alternately impinging THz radiation onto the tethered molecule and onto a sample including the tethered and untethered target molecules; (3) detecting the radiation impinged on the tethered molecule to form a reference signal and the radiation impinged on the sample to form a sample signal; and (4) comparing the reference signal with the sample signal to generate a specimen signal indicative of an association between the selected tethered and target molecules. The method will detect whether a selected tethered molecule and the desired target exhibit any affinity or, in cases where the affinity is known, will detect the presence of the target molecule in a sample. Also provided is an apparatus for detecting specific associations between a tethered molecule and an untethered target molecule.

Abstract: A diagnostic apparatus including a terahertz generator taking the form of a femtosecond laser exciting either an optoelectric crystal of a photoconductive dipole antenna the terahertz radiation is directed onto a target preferably held close by or abutting an enclosure including a reflection receiving window and housing terahertz detector for detecting terahertz radiation. Preferably the terahertz radiation generator forms part of the receiving window. The enclosure has a modified atmosphere to permit ready transmission of terahertz radiation. A beam splitter is positioned between the laser and the terahertz generator to split off a probe laser beam from the terahertz inducing laser radiation which is also directed to the detector means. The output from the detector being determined by the amplitude of that part of the reflected teraherz radiation wave coaligned with the probe laser at the detector.

Abstract: A diagnostic apparatus including a terahertz generator taking the form of a femtosecond laser exciting either an optoelectric crystal of a photoconductive dipole antenna the terahertz radiation is directed onto a target preferably held close by or abutting an enclosure including a reflection receiving window and housing terahertz detector for detecting terahertz radiation. Preferably the terahertz radiation generator forms part of the receiving window. The enclosure has a modified atmosphere to permit ready transmission of terahertz radiation. A beam splitter is positioned between the laser and the terahertz generator to split off a probe laser beam from the terahertz inducing laser radiation which is also directed to the detector means. The output from the detector being determined by the amplitude of that part of the reflected teraherz radiation wave coaligned with the probe laser at the detector.