Meusel M, Trau D, Katerkamp A, Meier F, Polzius R, Cammann K
SENSORS AND ACTUATORS B-CHEMICAL 51 (1-3): 249-255 AUG 31 1998
Cited References: 18 Times Cited: 11 (at November 2005)
Abstract: An optical immunosensor system consisting of a disposable low-cost sensor chip including a fluidic system and a base unit for optical readout was developed. Near infrared (NIR)-fluorescence markers (Cy5) were excited by an evanescent wave generated on the surface of the sensor chip. The combination of both fluorescence measurements and evanescent wave excitation provides extremely sensitive detection and avoids any washing or separation steps. To demonstrate the feasibility of the system for environmental control assays for the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) were developed. Two different assay formats were applied to determine 2,4-D in the relevant concentration range. Due to the assay formats chosen a direct proportional relationship between analyte concentration and signal intensity was achieved. Within an assay time of 15 min only, the analyte 2,4-D could be determined in a linear concentration range covering three orders of magnitude. (C) 1998 Elsevier Science S.A. All rights reserved.
Author Keywords: optical immunosensor; fluorescence label; evanescent wave; environmental analysis; 2,4-dichlorophenoxyacetic acid