Sensitive and Quantitative Determination of Cardiac Troponin I Based on Silica-Encapsulated CdSe/ZnS Quantum Dots and a Fluorescence Lateral Flow Immunoassay

摘要

Cardiac troponin I is generally used as a biomarker of myocardial infarction or acute myocardial infarction.A timely and rapid diagnosis method for cardiac troponin I is of great importance.In this paper,a novel CdSe/ZnS quantum dot (QD) based fluorescence lateral flow immunoassay (QD-LFIA) is reported for the rapid and quantitative detection of cardiac troponin I in human serum.The water-soluble silica- encapsulated QDs (QDs@SiO_2) serve as a new fluorescent probe and an economical,portable,quantitative instrument was used for the first time to detect cardiac troponin I antigen.By using the optimized immunoassay procedure with clinical samples,cardiac troponin I was determined in 10 min with high sensitivity (as low as 5.6×10~(-3) ng/ mL),broad linear range (0.8–200 ng/mL),and good precision (the coefficient of variation was less than 10%).The comparison of this new QD-LFIA and a standard direct chemiluminescence assay demonstrated that the former platform was rapid,low-cost,and sensitive.It may be further applied to the quantitative determination and monitoring of cardiac troponin I levels in clinical use.