Data_Sheet_1_High-Sensitivity Detection of the Lung Cancer Biomarker CYFRA21-1 in Serum Samples Using a Carboxyl-MoS2 Functional Film for SPR-Based Immunosensors.DOCX

We constructed a novel surface plasmon resonance (SPR) detection assay using carboxyl-functionalized molybdenum disulfide (carboxyl-MoS2) nanocomposites as a signal amplification sensing film for the ultrasensitive detection of the lung cancer-associated biomarker cytokeratin 19 fragment (CYFRA21-1). The experiment succeeded in MoS2 reacted with chloroacetic acid giving carboxyl-MoS2 as the reaction product. The additional shoulder in the C 1s and O 1s peaks of carboxyl-MoS2, which were increased in X-ray photoelectron spectroscopy, confirmed the presence of O–C=O groups on the surface of the carboxyl-MoS2. Compared to MoS2, the experimental results confirmed that carboxyl-modified MoS2 had improved low impedance and low refractive index. The carboxyl-MoS2-based chip had a high affinity, with an SPR angle shift enhanced by 2.6-fold and affinity binding KA enhanced by 15-fold compared to a traditional SPR sensor. The results revealed that the carboxyl-MoS2-based chip had high sensitivity, specificity, and SPR signal affinity, while the CYFRA21-1 assay in spiked clinical serum showed a lower detection limit of 0.05 pg/mL and a wider quantitation range (0.05 pg/mL to 100 ng/mL). The carboxyl-MoS2-based chip detection value was about 104 times more sensitive than the limit of detection of an enzyme-linked immunosorbent assay (ELISA) (0.60 ng/mL). The results showed that the carboxyl-MoS2-based chip had the potential to rapidly assay complex samples including bodily fluids, whole blood, serum, plasma, urine, and saliva in SPR-based immunosensors to diagnose diseases including cancer.

本研究构建了一种新型表面等离子体共振（Surface Plasmon Resonance, SPR）检测方法，以羧基功能化二硫化钼（carboxyl-MoS2）纳米复合材料作为信号放大传感薄膜，用于超灵敏检测肺癌相关生物标志物细胞角蛋白19片段（CYFRA21-1）。实验通过二硫化钼与氯乙酸反应，成功制备得到羧基-MoS2产物。X射线光电子能谱（X-ray Photoelectron Spectroscopy, XPS）检测结果显示，羧基-MoS2的C 1s与O 1s特征峰出现额外肩峰，且峰强度提升，证实其表面存在O–C=O基团。相较于未修饰的二硫化钼，实验结果证实羧基改性二硫化钼的阻抗与折射率均更低。基于羧基-MoS2的SPR芯片展现出优异的亲和性能：与传统SPR传感器相比，其SPR角位移提升2.6倍，亲和结合常数KA提升15倍。研究结果表明，基于羧基-MoS2的SPR芯片具备高灵敏度、高特异性与优异的SPR信号亲和性；在加标临床血清样本的CYFRA21-1检测实验中，该方法的检出限低至0.05 pg/mL，定量范围更宽（0.05 pg/mL至100 ng/mL）。该芯片的检测灵敏度约为酶联免疫吸附试验（Enzyme-Linked Immunosorbent Assay, ELISA）检出限（0.60 ng/mL）的104倍。研究结果证实，基于羧基-MoS2的SPR芯片具备应用潜力，可在基于SPR的免疫传感器中快速检测包括体液、全血、血清、血浆、尿液与唾液在内的复杂样本，进而实现包括癌症在内的多种疾病的临床诊断。