A cell-based electrochemical sensor for assessing immunomodulatory effects by atrazine and its metabolites

A three-dimensional (3D) cell-based electrochemical sensor was developed to evaluate the immunomodulatory effects of atrazine and its metabolites by monitoring nitric oxide (NO) release. Nafion/Fe(III) meso-tetra (4carboxyphenyl) porphyrin/reduced graphene oxide (Nafion/FeTCP@RGO) was functionalized on the screen printed carbon electrode (SPCE) as a working electrode to enhance the NO selectivity and sensitivity. RAW264.7 cells encapsulated in a gelatin methacrylate (GelMA) hydrogel, forming a 3D cell culture system, were immobilized on the Nafion/FeTCP@RGO/SPCE to serve as biorecognition elements. The proposed sensor presented the induced NO expression as a distinct single differential pulse voltammetric (DPV) anodic peak in the selected physiological lipopolysaccharide (LPS) concentration range (0.01-2000 ng/mL). Furthermore, the peak current intensity of the NO was linearly correlated with the LPS concentration logarithm, which was further validated using a Griess reagent kit. The proposed sensor was utilized in optimized LPS-induction conditions to compare the immunosuppression effect of atrazine with its main metabolites (i.e. desethylatrazine (DEA), deisopropylatrazine (DIA), and diaminochlorotriazine (DACT)). The results demonstrated that the order of 30% inhibitory concentrations was atrazine (25.71 +/-& nbsp;1.08 mu g/mL) < DEA (48.63 & PLUSMN; 2.17 mu g/mL) <=& nbsp;DACT (49.11 & nbsp;+/- 1.98 mu g/mL) <=& nbsp;DIA (52.36 & nbsp;+/- 2.34 mu g/mL). Overall, this work provided a potential in vitro approach to evaluate the immunotoxicity of pesticides and their metabolites.

Automated summary

A 3D cell-based electrochemical sensor was developed to evaluate the immunomodulatory effects of atrazine and its metabolites by monitoring nitric oxide release. The sensor showed high selectivity and sensitivity in detecting nitric oxide, and was used to compare the immunosuppression effect of atrazine and its metabolites.