AFB1 colorimetric aptamer sensor for the detection of AFB1 in ten different kinds of miscellaneous beans based on gold nanoparticles and smartphone imaging

A simple, rapid, low-cost, sensitive, intuitive, visual, label-free, colorimetric smartphone-assisted assay was developed for the measurement of aflatoxin B1 in miscellaneous beans. Ten different kinds of miscellaneous beans were treated and measured by modified QuEChERS(Quick、Easy、Cheap、Effective、Rugged、Safe) method with aflatoxin B1 nucleic acid aptamer as a recognition element and gold nanoparticles as indicators. Several factors influencing its sensitivity were investigated, including consumes and NaCl concentrations, as well as incubation time and specificity. The results showed a good linear relationship between concentrations of 0.2–8.0 ng/g under optimal conditions. With a detection limit of 0.08 ng/g, the linear regression equation was Y = 0.024X + 0.4615 (R = 0.9989). Sensor specificity is good. The content of aflatoxin B1 in bean samples was determined successfully. The recovery of aflatoxin B1 ranged from 87.18% to 110.24%. The whole thing took 15 min. This smartphone-assisted colorimetric aptamer sensor can be used to detect aflatoxin B1 in beans.