Label–free electrochemical immunosensor for porcine gelatin using a boron–doped diamond electrode viadiazonium salt electrografting
Irkham, Fadli Taufik Abdillah, Muhammad Ihda H. L. Zein, Adisyahputra, Nazwa Alya Zahra, Salma Nur Zakiyyah and Yeni Wahyuni Hartati
https://doi.org/10.5599/jese.2720
Abstract
Porcine gelatin is widely used in the food and pharmaceutical industries due to its favorable functional properties and low cost. However, its presence in consumer products raises serious concerns for individuals with dietary restrictions based on religious, ethical, or health considerations. In this study, a label-free electrochemical immunosensor was developed using a boron-doped diamond electrode modified with aryl diazonium salt for the selective and sensitive detection of porcine gelatin. The diazonium electrografting enabled stable covalent immobilization of anti-porcine gelatin antibodies via protein A, preserving antibody orientation and activity. Experimental parameters were optimized using the Box-Behnken design, yielding ideal conditions of 500× antibody concentration, 60 min antibody incubation, and 15 min 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 immunosensor demonstrated excellent analytical performance, with a detection limit of 142.15 pg mL-1. Specificity testing confirmed that the sensor responds exclusively to porcine gelatin, showing no cross-reactivity with bovine gelatin. These results demonstrate that the proposed immunosensor provides a rapid, highly sensitive, and specific platform for porcine gelatin detection, offering great potential for food authentication and halal verification.
Keywords:
Modified diamond electrode; diazonium derived film; pork skin gelatin; food authentication