Abstract
In silico evaluation of aptamer/target interactions can facilitate the development of efficient biosensor with high specificity and affinity. In this work, we present in silico, i.e. structural similarity, molecular docking and molecular dynamics selection of the aptamer with sufficient binding properties for acetamiprid (ACE), a nicotine-like pesticide, and its use to design aptamer–modified magnetic beads bearing ferrocene co–immobilized label for capacitive detection of ACE. Taking advantages of the aptamer higher stability and binding affinity, the specific properties of magnetic beads and the redox properties of ferrocene moiety, the developed aptasensor showed promising analytical performances for ACE detection, using electrochemical capacitance spectroscopy, with a linear response ranging from 1 fM to 100 pM and a limit of detection of 0.94 fM (S/N = 3). Furthermore, it was successfully applied to detect ACE in fortified tomatoes samples, proving a promising approach for routine detection of pesticide in real agricultural samples.
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•Bioinformatics tools were used to choose between two aptamers with different lengths.•Knowledge-based choice allowed to select the shorter aptamer for the biosensor design.•Acetamiprid sensing is based on electrochemical capacitance spectroscopy.•The target was detected selectively in the 1 fM to 100 pM range.•The method was used to detect acetamiprid in fortified tomatoes sample.