A Novel Paper-Based Capacitance Mast Cell Sensor for Evaluating Peanut Allergen Protein Ara h 2

A novel paper-based capacitance mast cell sensor has been designed and developed for real-time monitoring of the major peanut allergen Ara h 2. In this study, we created the 3D paper chip printed with carbon electrodes as a non-contact capacitance sensing platform. To improve the conductivity and biocompatibility of the cellulose paper, a polyvinyl alcohol (PVA)-gelatin methacryloyl (GelMA)-nano-hydroxyapatite (nHAP) composite hydrogel (PGHAP gel) was employed to fabricate the prepared paper chip. When rat basophilic leukemia mast cells (RBL-2H3) are immobilized and cultured in the 3D culture system consisting of PGHAP gel and paper fibers, identification signals of Ara h 2 could be specifically monitored non-contact and real-time by capacitance change measurement. This 3D structure combined with time-lapse monitoring completes the capacitance cell sensor. Results indicate that Ara h 2 has given a remarkable decrease to the capacitance in dose-dependent range from 0.1 to 100 ng/mL. Therefore, the real-time cell allergic response could be accurately monitored by this low-cost, disposable cell sensor, which supplies a novel and effective pathway for the rapid and accurate evaluation for food allergens.