Development of two immunochromatographic test strips based on gold nanospheres and gold nanoflowers for the rapid and simultaneous detection of aflatoxin B1 and aristolochic acid a in dual-use medicinal and food ingredients

Rapid, low-cost, and easy to use methods are required to detect small-molecule toxins. In this study, gold nanospheres (AuNSs) and gold nanoflowers (AuNFs) were synthesized and used to develop two immunochromatographic test strips (ICS) based on gold nanospheres (SICS) and gold nanoflowers (FICS) for the rapid simultaneous detection of aflatoxin B 1 (AFB 1 ) and aristolochic acid (AA-A) in dual-use medicinal and food ingredients. For the detection of AFB 1 and AA-A, FICS (0.1 ng/mL for both AFB 1 and AA-A) had a sensitivity up to 5 times and 50 times higher, respectively, than that of SICS (0.5 ng/mL for AFB 1 and 5 ng/mL for AA-A). Moreover, the results of SICS and FICS with high-performance liquid chromatography showed good consistency, and there were no false positives or negatives. Gold nanoflower-based ICSs have the potential to be used on-site for detection with higher sensitivity requirements.