MXene catalyzed Faraday cage-type electrochemiluminescence immunosensor for the detection of genetically modified crops

Herein, a MXene catalyzed Faraday cage-type electrochemiluminescence (ECL) immunosensor was developed for the detection of transgenic component Cry1Ab protein in genetically modified (GM) crops. The capture unit Fe3O4-Ab(1) is Fe3O4 nanoparticles coated by capture antibody Ab(1), while the signal unit MXene-PTCA-Ab(2) is two-dimensional conductive material MXene with ECL labels 3,4,9,10-perylenetetracarboxylic acid (PTCA) and recognition antibody Ab(2) simultaneously immobilized. In presence of the target Cry1Ab, the Faraday cage-type electrochemical immunosensor could be constructed by forming the capture unit-Cry1Ab-signal unit immuno-complex. In addition to the inherently high sensitivity brought by the Faraday cage-type sensor construction mode, MXene in the signal unit catalyzes the reduction of dissolved O-2 to form reactive oxygen species which could accelerate the ECL reaction, resulting in a secondary ECL enhancement of PTCA and ensuing higher detection sensitivity. Under the optimized experimental conditions, Cry1Ab protein and GM maize MON810 could be quantitatively detected in the range of 0.005 -100 ng mL(-1) and 0.005 % -2.0 %, with limit of detections (LODs) 0.001 ng mL(-1) and 0.001 % respectively. Selectivity, stability, repeatability, precision, and accuracy are all satisfactory. Detection of actual samples is successful, showing its application prospect in the field of agriculture and food safety.

Automated summary

A MXene-catalyzed immunosensor was developed for detecting Cry1Ab protein in GM crops, showing high sensitivity and detection capability. The sensor structure, combined with MXene catalysis, enhances the ECL reaction for improved detection sensitivity. The system demonstrated satisfactory performance in terms of selectivity, stability, repeatability, precision, and accuracy, with successful detection of actual samples.