Pressure/colorimetric dual-readout immunochromatographic test strip for point-of-care testing of aflatoxin B1

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 B-1 (AFB(1)) by using dendritic platinum nanoparticles (DPNs) as novel pressure/colorimetric dual-readout probes. DPNs-labeled antibody of AFB(1) 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 AFB(1). The proposed ITS was successfully utilized for detecting AFB(1) 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.

Automated summary

A sensitive immunochromatographic test strip (ITS) for detecting AFB(1) using dendritic platinum nanoparticles as pressure/colorimetric dual-readout probes was developed. The ITS showed a detection range of 0.05-10 ng mL(-1) with a detection limit of 0.03 ng mL(-1) for AFB(1). It was successfully utilized for detecting AFB(1) in herbal medicine samples, demonstrating its reliability for real sample detection and potential applications in drug and food quality control, pollutants monitoring, and medical diagnosis.