Development of a living mammalian cell-based biosensor for the monitoring and evaluation of synergetic toxicity of cadmium and deoxynivalenol.

With increased interest in the toxic interactions of multiple toxins, biotoxicity models have to be urgently developed for joint toxicity evaluation. This study aimed to develop an optical biosensor based on living mammary cells for monitoring of cadmium (Cd)/deoxynivalenol (DON) in water and evaluating their combined toxicity. Our previous survey found that DON and Cd appeared simultaneously in various products, and RNA seq revealed that AP-1 participated in combined toxicity of DON+Cd in HT-29 cells. Thus AP-1 site-mCherry-based biosensors were constructed, optimized, and then tested for their applicability and stable fluorescence response activities. DON+Cd2+, DON, and Cd2+ induced dose-dependent fluorescence signal in the biosensors (at environmental exposure levels). The enhanced fluorescence signal suggested that the toxicity of DON+Cd2+ was enhanced compared with that of single toxin. The advantages of the biosensors include: I) The easy and visual screening of multiple toxins on the basis of environmental exposure levels; II) Potential as a broad-spectrum tool for joint toxicity evaluation of DON+Cd; III) Pollution-free and stable fluorescence response; IV) A slight effect on viability.