An electrochemical biosensor for on-glove application: Organophosphorus pesticide detection directly on fruit peels

One of the greatest challenges for the future is represented by the conservation of global agricultural production: it is necessary to implement early monitoring of the health conditions of crops through innovative technologies that allow a sustainable development. To reach this goal, the development of portable biosensors might represent a robust strategy for monitoring agricultural sites in agreement with the requirement of precision agriculture. In this work, an electrochemical inhibition biosensor has been engineered onto a glove to quantify organophosphorus pesticides directly on fruits peels. The biosensor was obtained through modification with a bio-hybrid probe which included Prussian blue, Carbon black and butyrylcholinesterase enzyme. The detection concept is based on the inhibition of the enzyme in presence of the pesticide, namely dichlorvos. The experimental setup has been characterized and the ultimate on-glove configuration has been applied towards the detection of dichlorvos directly on fruit peels, namely apples and oranges. The only task required for the end-user was to scrub the surface of the fruit with the strip and performing the electrochemical reading. The portable system was characterized by a low detection limit in the nanomolar range (high ppt) and a satisfactory repeatability lower than 10 %. It represents the starting point towards the design of on-glove biosensors in many fields of application, including the precision agriculture.