This paper (open access) reports the development of a label-free electrochemical immunosensor for the detection of low quantities of porcine gelatin. The sensor is based on a boron-doped diamond electrode modified with aryl diazonium salt. The diazonium electrografting enabled stable covalent immobilization of anti-porcine gelatin antibodies via protein A, preserving antibody orientation and activity.
The optimised conditions were a 500× antibody concentration, 60 minute antibody incubation, and 15 minute gelatin incubation. Detection was performed using differential pulse voltammetry with [Fe(CN)₆]3-/4- as a redox probe, allowing label-free monitoring of antibody-antigen interactions based on changes in current.
The authors report that the immunosensor demonstrated excellent analytical performance, with a detection limit of 142.15 pg mL-1. Specificity testing showed no cross-reactivity with bovine gelatin.
Although suitable validation would be required, the authors conclude that this immunosensor has potential to form the basis of a rapid, highly sensitive, and specific platform for porcine gelatin detection, offering great potential for food authentication and halal verification.
