Abstract: Chemiluminescent immunoassays(CLIA) were intensively studied in antigen/antibody detection, due to the extremely sensitive chemiluminescent detection techniques. Here we present a sensitive immuno-assay for cTnI based on this concept. The assay was executed as the traditional ELISA except that two major modifications were made to obtain a rapid test and a high sensitivity. The first modification is that the two-step dual monoclonal antibody “sandwich” principle of traditional ELISA was substituted by a one-step immuno-reaction mode which decreased the turnaround time greatly. The second modification is that a chemiluminescent substrate(AMPPD) and chemiluminescent detection techniques, which elevated the sensitivity remar-kably, were used to replace the colorimetric substrate and colorimetric detection method in ELISA. The detection procedure of the assay could be fulfilled within 75 min. A linear range between the luminescent signal current and the concentration of cTnI from 0.04 to 36.2 ng/mL and a detection limit of 0.02 ng/mL were obtained. The established method was tested by determining cTnI in real samples by using ELISA for comparison analysis, and good results were obtained.

Key words: Chemiluminescent immunoassay, Acute myocardial infarction, AMPPD, Cardiac troponin I(cTnI)