Tissue- and microbe-based electrochemical detectors for liquid chromatography

A novel electrochemical detection approach for liquid chromatography is described, utilizing rapid-responding tissue- and microbe-based carbon paste electrodes. This approach adds a new dimension of selectivity to liquid chromatography/electrochemistry, based on bioactivity (substrate specificity). Complex chromatograms (e.g., of urine samples) are greatly simplified as only substrates of the enzymes present in the cellular material are detected. Selectivity can be greatly improved by obtaining two chromatograms, one profiling only the biologically active solutes. Because of their higher enzymatic activity and stability, cellular materials are more suitable for liquid chromatographic detection than isolated enzymes. This concept is tested on several classes of analytes, using banana-, mushroom- and yeast-modified electrodes. Results are also given for a series configuration with a tissue-generator/electrode collector. These developments should lead to increased use of natural materials for monitoring chromatographic effluents.