A smartphone-assisted colorimetric aptasensor based on aptamer and gold nanoparticles for visual, fast and sensitive detection of ZEN in maize

A simple, fast, low cost, sensitive, intuitive, visual, label-free, and smartphone-assisted aptamer sensor based on colorimetric assay for the measurement of zearalenone was constructed. The nucleic acid aptamer of zearalenone was used as the recognition element and gold nanoparticles were used as the indicator. Several factors that could influence sensitivity, including the concentration of aptamer and NaCl, and incubation time, and specificity, have been investigated. The results showed that under the optimal conditions, the signal had a good linear relationship when zearalenone concentration is 5-300 ng/mL. A linear regression equation is Y = 0.0003X + 0.5128 (R2 = 0.9989) and a limit of detection is 5 ng/mL. The specificity of the sensor was good. Zearalenone in maize samples were successfully measured. The recoveries of Zearalenone are 81.3 %-96.4 %. The whole process takes only 15 min to complete. The smartphone assisted colorimetric aptamer sensor can be used for the detection of zearalenone in maize.

Automated summary

A simple, fast, low-cost, sensitive, intuitive, visual, label-free, and smartphone-assisted aptamer sensor based on colorimetric assay was developed for measuring zearalenone in maize. The sensor utilized a nucleic acid aptamer as the recognition element and gold nanoparticles as the indicator. Various factors including aptamer and NaCl concentration, incubation time, and specificity were investigated. The results demonstrated a good linear relationship between the signal and zearalenone concentration (5-300 ng/mL) under optimal conditions, with a linear regression equation of Y = 0.0003X + 0.5128 (R2 = 0.9989) and a limit of detection of 5 ng/mL. The sensor exhibited good specificity and successfully measured zearalenone in maize samples, achieving recoveries of 81.3% - 96.4%. The entire process could be completed within 15 minutes. This smartphone-assisted colorimetric aptamer sensor holds promise for zearalenone detection in maize.