Production of an Electrochemical Sensor for Microcystin Measurement Using AuNPs@MWCNTs/GQDs Nanocomposites - A Review

This review paper focuses on the current state of art as well as on future trends in the reaction mechanism and detecting properties of a novel molecular printed electrochemical sensor for microcystin measurement using three-dimensional (3-D) AuNPs@MWCNTs/GQD nanocomposite. Microcystins (MCs) are secondary metabolites generated by some cyanobacteria, a stable cyclic heptapeptide toxin class in the environment. MCs can produce a wide various adverse health effects in animals, plants and humans. Effective methods and measurement techniques required for isolate MCs from the contaminated aquatic environments. Among the methods, the sensor with three-dimensional conductive network composed of multi-walled carbon nanotubes (MWCNTs), graphene quantum dots (GQDs), and gold nanoparticles (AuNPs) and AuNPs@MWCNTs/GQDs Nanocomposites, some microorganisms with enzymes; it was was found that AuNPs@MWCNTs/GQDs is the most sensitive one. The molecularly imprinted polymer was engineered by quantum chemical computation utilizing p-aminothiophenol (p-ATP) and methacrylic acid (MAA) as dual functional monomers and L-arginine as a segment template with irreversible electrochemical oxidation reaction involving an electron and two protons. The detection response to MC-LR in the linear range was between 0.08 and 2 μg/l, and the limit of detection (LOD) was found to be 0.0027 μg/l (S/N = 3). In addition, the recoveries of the total amount of MC-LR and [Dha7] MC-LR in the actual sample by the obtained sensor were found to be higher than the other methods.