Pressure/colorimetric dual-readout immunochromatographic test strip for point-of-care testing of aflatoxin B(1).

Affiliation

Jiang S(1), Zhang L(1), Li J(1), Ouyang H(1), Fu Z(2).
Author information:
(1)Key Laboratory of Luminescence Analysis and Molecular Sensing
(Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400716, China.
(2)Key Laboratory of Luminescence Analysis and Molecular Sensing
(Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing, 400716, China. Electronic address: [Email]

Abstract

Immunochromatographic test strip (ITS) for point-of-care testing (POCT) has attracted prominent attention due to the advantages including rapid response, low cost and good portability. Here, we developed a sensitive ITS for detecting aflatoxin B1 (AFB1) by using dendritic platinum nanoparticles (DPNs) as novel pressure/colorimetric dual-readout probes. DPNs-labeled antibody of AFB1 were used as the signal tracer of the immunochromatographic process. After 10-min competitive immunoreaction, black color appeared on the test line of ITS due to the accumulation of DPNs, which was observed visually as a colorimetric readout for qualitation purpose. Furthermore, DPNs with peroxidase-like activity caused decomposition of hydrogen peroxide aqueous solution to produce pressure change signal in vials, which was detected by a hand-held pressure meter for quantitation purpose. With the pressure readout mode, the detection range was 0.05-10 ng mL-1, and the detection limit was 0.03 ng mL-1 (S/N = 3) for AFB1. The proposed ITS was successfully utilized for detecting AFB1 in herbal medicine samples, and the acceptable recoveries of 93.77-114.09% indicated the reliability for real sample detection. It provides a new avenue for POCT with great application potential in various area including drug and food quality control, pollutants monitoring as well as medical diagnosis.