G. Gauglitz, A. Brecht, G. Kraus, and W. Nahm. Chemical and biochemical sensors based on interferometry at thin (multi-) layers. In Sensors and Actuators B: Chemical, vol. 11(1) , pp. 21-27, 1993
Spectral interferometry is presented as a tool to monitor the swelling of polymers caused by organic gases or hydrocarbons in waste water as well as the adsorption and interaction of antigens and antibodies in immunoreactions. Modern diode-array technology allows the consequent observation of changes in optical pathlength on a fractional nanometer scale with subsecond repetition times. The theory of multiple-reflection principles in white-light interferometry determines the possibilities and limitations of this method. The optical set-up and some applications in gas sensing and label-free immunosensing are discussed with respect to the sensitivity, selectivity and limits of detection at present.