Development of an Impedimetric Immunosensor for Specific Detection of Snake Venom

Abstract

Serotherapy is the only approved method to treat victims of snakebites; therefore, it is very important to identify the type of venom implicated in the accident to ensure the most specific antivenom is administered to the patient. In Brazil, the majority of snakebite accidents are from snakes of Bothrops genus. In this work, we developed an immunosensor capable to recognize specifically venoms from Bothrops snakes based on the electrochemical impedance spectroscopy technique. For this, Crofer 22 APU steel was used as transducer substrate functionalized with antibothropic antibodies. The immunosensor was incubated with different concentrations of venoms from Bothrops, Crotalus, and Micrurus in order to evaluate its specificity. The formation of the antigen-antibody immunocomplex at the surface of the transducer substrate increased the leakage resistance in a concentration-dependent manner when the device was exposed to the bothropic venom, while no considerable variation of this parameter could be observed for the venoms of the heterologous genera. In addition to the observed specificity, the sensor proved reusable, since the immersion in an elution buffer permitted many regeneration and charge cycles without considerable loss of activity. The results strongly indicated that the developed immunosensor stands as a promising device to aid in snakebites diagnosis.