A highly sensitive photothermal immunochromatographic sensor for detection of aflatoxin B1 based on Cu2-xSe-Au nanoparticles.

• Cu 2-x Se-Au with 60.78% photothermal conversion efficiency was synthesized. • A new photothermal immunosensing probe was prepared. • IC 15 of photothermal immunochromatographic sensor for aflatoxin B1was 0.00842 μg/L. • The detection ranging to analysize grain sample is from 0.16 to 160μg/kg. In the study, Cu 2-x Se-Au nanoparticles (CSA) with a photothermal conversion efficiency of 60.78 % at 808 nm were applied to the construction of thermal analysis immunochromatographic test strips for the highly sensitive quantitative detection of aflatoxin B 1 (AFB 1) in grain. The CSA was coupled with the AFB 1 antibody to form a photothermal sensor probe by physical adsorption. The constructed immunosensor exhibited high sensitivity and a wide linear range from 0.01 to 10 μg/L in PBS. The detection limits of 0.00842 μg/L based on the thermal analysis was significantly improved by 11.88-fold compared with colorimetric results. No cross-reaction with the other mycotoxins was found except for aflatoxin B 2 , aflatoxin M 1 , aflatoxin G 1 and aflatoxin G 2. Applied to analysize grain sample, the method achieved the detection of AFB 1 ranging from 0.16 to 160 μg/kg. [ABSTRACT FROM AUTHOR]