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

Abstract

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@SiO₂) 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.

Keywords:

• Cardiac troponin I
• quantum dots
• QD-based lateral flow immunoassays

Acknowledgements

The authors gratefully acknowledge the financial support from the research project of 113 Talents Program of China Medical City, Program for High-Level Innovation and Entrepreneurship of Jiangsu Province and the National Natural Science Foundation of China.

Additional information

Funding

Funded by the research project of 113 Talents Program of China Medical City, Program for High-Level Innovation and Entrepreneurship of Jiangsu Province and the National Natural Science Foundation of China (21671058 and 81902158).