Impedimetric nanostructured genosensor for detection of schistosomiasis in cerebrospinal fluid and serum samples

Schistosomiasis is a neglected disease closely related to the low levels of social development and a serious public health problem. In this work, we performed an electrochemical detection of Schistosoma mansoni DNA with a self-assembled monolayer of mercaptobenzoic acid (MBA) immobilizing nanostructures composed of gold nanoparticles (AuNPs) and magnetite nanoparticles (Fe₃O₄_NPs). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to monitor the hybridization process. MBA-Fe₃O₄_NPs-AuNPs-DNAprobe system reveals an effective electrochemical response indicating the surface modification. The proposed biosystem was capable to recognize specific nucleotide sequence of S. mansoni present in cerebrospinal fluid (CFS) and serum samples at different genome DNA concentrations. The biorecognition resulted in an increase in the electron transfer resistance and a decrease of the current peaks at higher DNA concentrations during electrochemical measurements. The developed platform showed a DNA detection limit of 0.781 and 0.685pgμL^-1 for serum and CFS, respectively. Therefore, the obtained biosensor can be considered as a useful tool for specific detection of S. mansoni at low concentrations in various biological fluids.