An aptasensor with colorimetric and electrochemical dual-outputs for malathion detection utilizing peroxidase-like activity of Fe-MOF.

An aptasensor with dual-outputs was developed for malathion detection. Fe-MOF was synthesized to design favorable signal probes for catalytic amplification. Owing to the excellent peroxidase-like activity of Fe-MOF, the redox reaction was catalyzed to produce the dual-outputs of colorimetric and electrochemical. In this sensing strategy, malathion was captured by the aptamer on sensing interface, leading to the release of signal probe. Thanks to the catalytic amplification of Fe-MOF and the high capture effect of aptamer, the aptasensor produced a sensitive response for malathion. Based on the dual-signals of absorbance and current, the detection method for malathion was developed ranging from 10 ng/mL to 500 ng/mL. The detection limit of malathion was 5.8 ng/mL for colorimetric output and 4.6 ng/mL for electrochemical output. Furthermore, the aptasensor exhibited high specificity and good repeatability in malathion detection. Finally, the aptasensor was applied to detect malathion in fruit and vegetable samples with satisfactory recovery.