A 5-Hydroxytryptamine Release-Based Biomimetic Microtissue Sensor for Detecting Creatine Kinase

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.