An ultrasensitive label-free electrochemical immunosensor using MoS₂/NiCo heterostructures as an efficient signal enhancer was proposed for sensitive detection of procalcitonin. The MoS₂/NiCo heterostructures were synthesized by thermally depositing MoS₂ on NiCo MOFs nanocubes, which were then functionalized with in situ grown palladium nanoparticles (Pd NPs) for electrochemically catalyze the reduction of hydrogen peroxide. The presence of MoS₂/NiCo heterostructures greatly enhanced the electrocatalytic activity of Pd NPs, thus the Pd NPs@MoS₂/NiCo modified electrode showed amplified response to hydrogen peroxide. The large specific surface of Pd NPs@MoS₂/NiCo greatly improved the loading of antibody for preparation of immunosensor. Upon the incubation of the immunosensor with target procalcitonin, the electron transfer impendence increased, and thus the chronoamperometric response decreased, leading to a highly sensitive immunosensing method for detection of procalcitonin. The proposed method showed a linear range of 0.001–50 ng/mL with a detection limit of 0.36 pg/mL (S/N = 3). It possessed excellent accuracy and good practicality for diagnostics of PCT related diseases, and could be extended for development of other immunosensors for biomarkers detection.

提出了一种以MoS ₂ / NiCo异质结构作为有效信号增强剂的无标记的超灵敏电化学免疫传感器，用于降钙素原的灵敏检测。通过在NiCo MOFs纳米立方体上热沉积MoS ₂合成MoS ₂ / NiCo异质结构，然后用原位生长的钯纳米颗粒（Pd NPs）对其进行功能化，以电化学催化过氧化氢的还原。MoS ₂ / NiCo异质结构的存在大大增强了Pd NPs的电催化活性，因此Pd NPs @ MoS ₂ / NiCo修饰电极对过氧化氢的反应增强。Pd NPs @ MoS ₂的大比表面积/ NiCo大大提高了制备免疫传感器的抗体负荷。在将免疫传感器与靶降钙素温育后，电子转移势力增加，因此计时电流法响应降低，从而导致用于检测降钙素的高度灵敏的免疫传感方法。所提出的方法的线性范围为0.001–50 ng / mL，检出限为0.36 pg / mL（S / N = 3）。它对PCT相关疾病的诊断具有极好的准确性和良好的实用性，并且可以扩展到其他用于生物标志物检测的免疫传感器的开发。