Based on the principle of creatine kinase (CK)-induced release of 5-hydroxytryptamine (5-HT) from mast cells, the quantitative analysis of CK was achieved by detecting changes in the oxidation current of 5-HT on the electrode surface. Gold nanoparticles (AuNPs), Fe₃O₄ nanoparticles and multi-walled carbon nanotube (MWCNT) were used jointly to modify the screen-printed carbon electrode (SPCE). Meanwhile, the composite of mast cells and gelatin methacryloyl (GelMA) was used as bio-ink to prepare a connective tissue model with a network structure through 3D bioprinting, which was then combined with an electrochemical workstation to develop a bionic sensor to detect CK. The sensor demonstrated a linear response to CK concentrations ranging from 0.3 to 5.0 μg/mL, which was fitted to the equation: I_DPV = 0.23639lgC + 1.94438 (R² = 0.993, n = 3). The limit of detection (LOD) was determined to be 0.042 μg/mL. The above results confirmed the feasibility of indirectly quantifying food allergen concentrations by detecting cellular secretion during allergic reactions. This study provides a new strategy for rapid allergen detection.

According to the hierarchical structure of the human skin, bionic skin microtissue with epidermal layer and subcutaneous tissue layer, which can simulate the reaction of the skin to food allergens, was bioprinted with human skin fibroblasts and RBL-2H3 cells and was used to construct a bionic skin electrochemical sensor by combined use of polypyrrole modification and rapid electrochemical detection technology. The results showed that the sensor could identify egg albumin well, and the linear range was 0.5–2.5 μg/mL. A linear regression equation was fitted as follows: y = 4.45C + 14.24, with a correlation coefficient (R²) of 0.998, and the detection limit of this method was 0.19 μg/mL. The successful construction of the electrochemical sensor shows the possibility of applying biological 3D printing technology to prepare multi-cell composite bionic structures.