Research creates biosensor for biological pest control.

The search for more sustainable alternatives to chemical pesticides has been gaining momentum in Brazilian scientific research. At the Federal University of São Carlos (UFSCar), a study developed in the Postgraduate Program in Chemistry (PPGQ) resulted in the creation of a biosensor capable of rapidly detecting natural compounds present in plant extracts with insecticidal potential.

The technology was developed by doctoral student Sean dos Santos Araújo and allows the identification of inhibitors of the acetylcholinesterase (AChE) enzyme — fundamental to the functioning of the nervous system of insects and considered a strategic target in the control of agricultural pests. According to the researchers, the tool can contribute to accelerating the development of new biopesticides.

The electrochemical biosensor, called Bio-AChE, is the result of a partnership between the Natural Products Laboratory (LPN-UFSCar) and the Bioanalytical and Electroanalytical Laboratory (LaBiE). The device uses a printed carbon electrode, modified with gold nanoparticles coated with glutathione, forming a suitable surface for enzyme immobilization.

One of the main challenges of the work was ensuring that AChE remained stable and biologically active in the sensor. “Immobilizing the biological component is a fundamental step to ensure the enzyme's stability and the reliability of the measurements,” explains Araújo. According to him, modifying the surface with gold nanoparticles was crucial to intensify the electrochemical response and guarantee the accuracy of the readings.

technology advantages

Among the advantages of the technology are the lower cost and operational simplicity, especially when compared to traditional techniques, such as bioaffinity chromatography, which require more complex equipment and higher investments.

To validate the biosensor's functionality, the researchers initially used azadirachtin, a natural compound extracted from the Azadirachta indica plant and recognized as an AChE inhibitor. After validation, extracts from Picramnia riedelli, Picramnia ciliata, and Toona ciliata were evaluated, showing inhibition rates between 41% and 55%, indicating potential for the development of bioinsecticides.

The study also allowed for the identification of specific compounds responsible for inhibiting the enzyme. The results were published in the journal Analytical methodsThe research was supervised by professors Ronaldo Censi Farias, João Batista Fernandes, Moacir Rossi Forim, and Maria Fátima Fernandes da Silva, from the Chemistry Department at UFSCar.

The project received support from Capes, CNPq, and Fapesp.

Further information can be found at doi.org/10.1039/D4AY02084G