Differential screening of the neurotoxicity of insecticides by means of a novel electrophysiological biosensor

摘要

More than 500 different organic chemical substances are used worldwide as pesticides in agriculture and veterinary science. There is increasing evidence that many of these compounds cause moderate to severe neurological damage, due to cytotoxic activity on the foetus or the adult. Conventional methods for assessing the neurotoxicity of pesticides and their residues are very elaborate, time-consuming and expensive. For this reason, a novel cell-based biosensory method has been developed, for the detection of pesticide residues based on the Bioelectric Recognition Assay, (BERA). Neuroblastoma N2a cells have been used, immobilized in calcium alginate gel in order to preserve their physiological functions. The avermectin abamectin was chosen as a model insecticide. Various operational parameters were investigated, such as assay temperature and electrode material. In its optimal configuration, the novel biosensor responded to different abamectin concentrations in a linear fashion, with satisfactory sensitivity (10 ppb) and at a considerably high speed (100-180 sec). The selectivity of the assay against a pyrethroid insecticide, a-cypermethrin, was also validated.