• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.544-547
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• 2014

In this study, an enzyme-linked immunosorbent assay (ELISA) and immuno-chromatographic technique were combined to fabricate immuno-strip sensors for the detection of Legionella pneumophila. The immuno-strip sensor was manufactured with four different membranes. A nitrocellulose membrane was used to immobilize capture antibody and generate signals due to the high affinity to antibodies, and glass fiber membranes were used as a conjugate release pad and a sample application pad. A cellulose membrane was used as an absorption pad to induce sample flow by the capillarity. Colorimetric signals produced by sandwich immuno-reaction and enzyme reaction could be analyzed qualitatively and quantitatively within 30 min. Under the given experimental conditions, sensor signals with L. pneumophila samples were observed qualitatively by naked eyes and measured quantitatively in a range of $1.3{\times}10^3-1.3{\times}10^6CFU/mL$ with a digital camera and home-made image analysis software.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.522-525
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• 2011

In this study, an established enzyme-linked immunosorbent assay and immuno-chromatography technique are combined to fabricate an immuno-strip sensor for the detection of S. aureus. The immuno-strip is manufactured by using four different functional membranes. The capture antibody is immobilized on the nitrocellulose membrane due to the high affinity and the capillary action through porous membranes induces a flow of sample. A colorimetric signal is appeared according to the enzyme reaction and is analyzed by the digital camera (qualitative analysis) and home-made image analysis software (quantitative analysis). Under the optimal conditions, samples with S. aureus in the range of $2.7{\times}10^4{\sim}2.7{\times}10^7CFU/mL$ can be detected by the colorimetric method within 30 min.