APPLICATION OF AN OPTICAL AND AN ELECTROCHEMICAL IMMUNOSENSOR FOR POLLUTION MONITORING IN THE NAIROBI RIVER

Authors: MULLA, FRANCIS - UNIVERSITY OF NAIROBI; WEBER, CRISTINA - CANDOR BIOSCIENCE GMBH; FORESTER, STEPHAN - CANDOR BIOSCIENCE GMBH; RAUCH, PETER - CANDOR BIOSCIENCE GMBH; ROBINSON, MARTIN - UNIVERSITY OF NEWCASTLE; MCNEIL, CALUM - UNIVERSITY OF NEWCASTLE; MUGE, EDWARD - UNIVERSITY OF NAIROBI; MADADI, VINCENT - UNIVERSITY OF NAIROBI; SHIUNDU', PAUL - UNIVERSITY OF NAIROBI; Stanker, Larry; KRAMER, PETRA - GSF-NATIONAL RES CENT

Submitted to: Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/5/2005
Publication Date: N/A
Citation: N/A

Interpretive Summary: Untreated river water is used in many slum areas along the Nairobi River. Pesticides in this water are of major health concern. This study demonstrates the application of two different simple immunosensors, one for measuring DDT and the second for measuring pyrethroid insecticide residues in the Nairobi River. These results demonstrate that the use of monoclonal antibodies as selective recognition components of the biosensors allow for a rapid determination of pesticide levels in the water. These results are compared with traditional chemical methods of analysis and a non-biosensor based immunoassay format. The limitations and overall strategy of river water monitoring using immunosensor technologies will be discussed.

Technical Abstract: Most communities living in slum areas along Nairobi River use untreated water for drinking and for domestic activities. Amongst other anthropogenic pollutions, pesticide residues are thus of major health concern. Present day techniques rely on chemical analysis, such as LC (liquid chromatography) and/or GC(gas chromatography). These methods need sophisticated instrumentation and usage of large volumes of organic solvents. Here we demonstrate the application of an optical and an electrochemical immunosensor (Fig. 1 A/B) as a complimentary technology for monitoring of DDT and pyrethroid residues in Nairobi River. Samples were collected at 10 sampling points along the river, starting from the source, and were analyzed by classical analysis and biosensor techniques. The results show that immunosensor technology, using monoclonal antibodies (mAbs) as selective recognition elements can be used to rapidly monitor pesticide residues in the water environment. The results are compared both with conventional ELISA (enzyme-linked immunosorbent assay) and GC analysis. The concentrations of DDT and pyrethroid residues in the river water were found to range from 0.3 to 3 µg/L. General pollution trend is: upstream < midstream < downstream. Advantages and limitations together with the overall strategy of river water monitoring using immunosensor technologies will be discussed.