Highly parallel affinity sensor for the detection of environmental contaminants in water

A parallel affinity sensor array (PASA) was implemented based on chemiluminescence labels (peroxidase/luminol) and CCD detection. Reagents like antibodies or haptens have been immobilized on a glass slide, which forms a biochip with an active area of about 1.8 cm(2). The spot density on the biochip was up to 9 spots per mm(2), which corresponds to an array of 1600 spots. Direct and indirect immunoassay formats have been tested successfully. Detection limits down to 20 ng l(-1) terbutylazine could be reached. The regeneration of the indirect assay chips could be performed more than 100 times. To improve the regenerability of direct assays an enzyme tracer with a cleavable spacer was introduced. The potential of the PASA for analyte identification by pattern recognition and subsequent analyte quantification could be shown. The application of the system is discussed for environmental, pharmaceutical, and other analytical fields. (C) 1999 Elsevier Science B.V. All rights reserved.