Detection of the pesticide by functionalised quantum dots as fluorescence-based biosensor

In this paper, we present the new results of biosensor that is made from the surface-modified quantum dots with acetylcholinesterase enzymes (AChE) for optical detection of the pesticides. The quantum dots (QDs) mentioned in this study are CdTe, CdSe/ZnS and CdSe/ZnSe/ZnS - the thick shell QDs are totally new. The results pointed out that all of the quantum dots are fit for the role of transducers in biosensor. In the biosensor, the QD-streptavidine - AChE is used as the substrate for the detection of pesticide. The pesticides used in this work are Parathion Methyl (PM) and Acetamiprid. The acetylthiocholine (ATCh) is used as an indicator of the activity of the AChE enzyme. Alternatively, the organophosphorus (OP) pesticides are the inhibitor for the AChE enzymes. Therefore, the mixture of the pesticide and ATCh is used for the goal of the specification of pesticide. We can detect pesticides by the change in PL intensity of QDs biosensor, with the content ranges from 0.05 ppb to 10 ppb.