Quantum Dot-Based Lateral Flow Test Strips for Highly Sensitive Detection of the Tetanus Antibody

Tetanus possesses a high infection rate and remains a leading cause of infection in some developing countries. To reduce tetanus infection, point-of-care (POC) monitoring of the serum tetanus antibody level is highly desired. Here, we report fluorescent lateral flow test strips (LFTS) for simple, sensitive, and rapid detection of the tetanus antibody. By using a sandwich immunoreaction, LFTS are easily prepared. In the existence of the tetanus antibody, goat anti-human IgG (Fc)-labeled quantum dots (QDs) are captured on the test line via the formation of a sandwich structure complex of QD-labeled goat anti-human IgG (Fc)-tetanus antibody-tetanus antigens. The assay can be completed in 30 min. These LFTS possess high sensitivity for tetanus antibody detection, with a detection limit of 0.001 IU mL(-1), which is 10 times lower than that of the Au nanoparticle-based test strip. The developed sensing system was also successfully applied for detection of the tetanus antibody in the human serum. Moreover, these strips can retain their specificity and sensitivity for at least 4 months when they are stored at 4 degrees C. All these results demonstrated that the LFTS can be used for detection of the tetanus antibody, and they exhibit great promise for in-field and POC application.