(4gk) Aptamer Based Pesticide Detection: Tri-Element Analysis

With advancements in the food industry, comes an associated malignant force of increased usage of pesticides and insecticides. Although usage of such substances bring about benefits such as that of pest/insect control and improved productivity, the disadvantages of the likes of food contamination and bio-magnification constitute one of the primary concerns in the field of food safety.

Conventional methods of pesticide detection include chromatography, spectrometry and fluorescence which succeed in terms of high effectiveness and accuracy, but fail in case of practical usage due to high complexity, being extremely time consuming, having a high cost of operation and requiring professional experts for conduction of such tests. Bio-chemical methods of pesticide detection are modern and promising solutions which overcome a majority of the shortcomings associated with the aforementioned conventional methods.

One such bio-chemical method is that of using “Apta-sensors” for the detection of pesticides which make use of single-stranded DNAs or RNAs, called Aptamers, with pesticide/chromatophore specific binding properties. We try to use MD simulations for finding out suitable Pesticide-Dye combination for aptamer based detection using Binding Energy (ΔG) as a basis for selection. Using appropriate hairpin structures of standard aptamers and positioning pesticide/dye molecules inside the appropriate loops, we study the interactions between the aptamer and the respective hetero-molecule for simulation runs of 25ns each.

Basis the interaction analysis, we were able to choose 2 dyes - Azobenzene and Sudan Orange G for use in the detection of Chlorpyrifos. We have also produced a strong theoretical basis for the selection of dyes using MD simulations.