A dual-mode label-free electrochemical immunosensor for ultrasensitive detection of procalcitonin by on-site vulcanization of dual-MOF heterostructure

Detection of procalcitonin (PCT) is crucial for the early identification of sepsis. PCT is primarily utilized in the multiple diagnosis of bacterial and viral illnesses along with to guide the application of antibiotics. Considering their advantages of high specificity and straightforward usage, electrochemical immunosensors offer significant application prospects in the detection of disease indicators. A dual-mode electrochemical immunosensor was constructed in this study to reliably identify PCT. In light of the synergistic effect of the dual-MOF derived heterostructure, the immunosensor demonstrating excellent square wave voltammetry (SWV) signals as well as significant catalytic activity for the H2O2 redox process. In addition to maintaining a low detection limit (SWV: 0.31 fg/mL and i-t: 0.098 fg/mL), the immunosensor offers an extensive linear response range (0.000001-100 ng/mL). The excellent performance is on account of the introduction of the local on-site sulfurized dual-MOF heterostructure with abundant metal chalcogenides/MOF interfaces, which boosts the specific surface area, offers an abundance of active sites, enhances conductivity, and raises catalytic activity. Furthermore, the immunosensor exhibits outstanding specificity, stability and reproducibility for the determination of PCT in serum, which is of great crucial for the clinical screening and diagnosis of sepsis.