Methylene blue (MB) adsorption onto a two-dimensional molybdenum disulfide (2D MoS₂)/graphene oxide (GO) nanocomposite sitting on a screen-printed carbon electrode (SPCE) is used to develop a new sensitive label-free electrochemical immunosensor for the detection of matrix metalloproteinase-7 (MMP-7) cancer biomarkers. The 2D MoS₂/GO nanocomposite deposited onto an SPCE provides a large specific surface area, fast electron transfer, and exceptional electrical conductivity. Furthermore, MB adsorbed onto the 2D MoS₂/GO nanocomposite architecture can be used for signal amplification in electrochemical immunosensors. Moreover, an immunosensor platform was fabricated by the adsorption of anti-MMP-7 capture antibodies onto the MB/2D MoS₂/GO nanocomposite surface via electrostatic interactions for the detection of the MMP-7 immunocomplex. Under optimum conditions, the label-free immunosensor exhibits a decrease in the current response for MB corresponding to the MMP-7 concentration. The sensor affords a linear logarithmic range of 0.010–75 ng mL⁻¹ with a limit of detection (LOD) of 0.007 ng mL⁻¹. The developed electrochemical immunosensor provides high selectivity, good reproducibility, and excellent stability. Furthermore, the proposed immunosensor can be applied for the detection of MMP-7 in human serum samples with good recovery. Thus, this device can be applied for the early clinical diagnosis of pancreatic and colorectal cancers.

亚甲基蓝 (MB) 吸附在位于丝网印刷碳电极 (SPCE) 上的二维二硫化钼 (2D MoS ₂ )/氧化石墨烯 (GO) 纳米复合材料上，用于开发一种新型灵敏的无标记电化学免疫传感器检测基质金属蛋白酶 7 (MMP-7) 癌症生物标志物。沉积在 SPCE 上的二维 MoS ₂ /GO 纳米复合材料提供了大的比表面积、快速的电子转移和出色的导电性。此外，吸附在二维 MoS ₂ /GO 纳米复合结构上的 MB 可用于电化学免疫传感器中的信号放大。此外，通过将抗 MMP-7 捕获抗体吸附到 MB/2D MoS _{2上来制造免疫传感器平台。}/GO 纳米复合材料表面通过静电相互作用检测 MMP-7 免疫复合物。在最佳条件下，无标记免疫传感器表现出与 MMP-7 浓度相对应的 MB 电流响应降低。该传感器提供 0.010–75 ng mL ^-1的线性对数范围，检测限 (LOD) 为 0.007 ng mL ^-1。开发的电化学免疫传感器具有高选择性、良好的重现性和出色的稳定性。此外，所提出的免疫传感器可用于检测人血清样品中的MMP-7，具有良好的回收率。因此，该装置可用于胰腺癌和结直肠癌的早期临床诊断。