Chemiluminescent enzyme-linked immunosorbent assay on a strip to detect Escherichia coli O157:H7

Abstract

A fast and sensitive chemiluminescent enzyme-linked immunosorbent assay method to measure pathogenic bacteria, Escherichia coli O157:H7, on immuno-chromatographic membrane was studied. Non-specific binding of proteins on membrane strip was controlled to attain the best performance of immunosensor by optimising the composition of a running buffer. The specificity of the proposed immunostrip was confirmed by conducting experiments for four different microorganisms. A chemiluminescent signal could be successfully generated from a proposed immunostrip sensing system, and a significant change in the chemiluminescent light intensity with the concentration of target microbes was obtained. E. coli O157:H7 could be quantitatively measured in the range of 1.1 x 10(3)-1.1 x 10(7) CFU (colony forming units) mL(-1) within 16 min by using the developed chemiluminescent immunostrip.