The thickness of the sensitive layer has an important influence on the sensitivity of a shear horizontal surface acoustic wave (SH-SAW) biosensor with a delay-line structure and lower layer numbers of graphene produce better sensitivity for biological detection. Therefore, a label-free and highly sensitive SH-SAW biosensor with chemical vapor deposition (CVD-)-grown single-layered graphene (SLG) for endotoxin detection was developed in this study. With this methodology, SH-SAW biosensors were fabricated on a 36° Y-90° X quartz substrate with a base frequency of 246.2 MHz, and an effective detection cell was fabricated using acrylic material. To increase the surface hydrophilicity, chitosan was applied to the surface of the SLG film. Additionally, the aptamer was immobilized on the surface of the SLG film by cross-linking with glutaraldehyde. Finally, the sensitivity was verified by endotoxin detection with a linear detection ranging from 0 to 100 ng/mL, and the detection limit (LOD) was as low as 3.53 ng/mL. In addition, the stability of this type of SH-SAW biosensor from the air phase to the liquid phase proved to be excellent and the specificity was tested and verified by detecting the endotoxin obtained from Escherichia coli (E. coli), the endotoxin obtained from Pseudomonas aeruginosa (P. aeruginosa), and aflatoxin. Therefore, this type of SH-SAW biosensor with a CVD-grown SLG film may offer a promising approach to endotoxin detection, and it may have great potential in clinical applications.

敏感层的厚度对具有延迟线结构的剪切水平表面声波 (SH-SAW) 生物传感器的灵敏度有重要影响，较低的石墨烯层数为生物检测提供更好的灵敏度。因此，本研究开发了一种无标记且高灵敏度的 SH-SAW 生物传感器，该传感器具有化学气相沉积 (CVD-) 生长的单层石墨烯 (SLG)，用于内毒素检测。使用这种方法，SH-SAW 生物传感器在 36° Y-90° X 石英基板上制造，基频为 246.2 MHz，并使用丙烯酸材料制造了有效的检测单元。为了增加表面亲水性，将壳聚糖应用于 SLG 膜的表面。此外，适体通过与戊二醛交联固定在 SLG 膜的表面。最后，通过内毒素检测验证了灵敏度，线性检测范围为 0 至 100 ng/mL，检出限 (LOD) 低至 3.53 ng/mL。此外，这种类型的 SH-SAW 生物传感器从气相到液相的稳定性被证明是非常好的，并且通过检测从大肠杆菌（E.coli）中获得的内毒素，测试和验证了特异性。铜绿假单胞菌 (P. aeruginosa) 和黄曲霉毒素。因此，这种带有 CVD 生长 SLG 膜的 SH-SAW 生物传感器可能为内毒素检测提供一种有前景的方法，并且在临床应用中可能具有巨大的潜力。证明这种类型的 SH-SAW 生物传感器从气相到液相的稳定性非常好，并且通过检测从大肠杆菌（E.coli）中获得的内毒素，从铜绿假单胞菌中获得的内毒素，测试和验证了特异性。铜绿假单胞菌）和黄曲霉毒素。因此，这种带有 CVD 生长 SLG 膜的 SH-SAW 生物传感器可能为内毒素检测提供一种有前景的方法，并且在临床应用中可能具有巨大的潜力。证明这种类型的 SH-SAW 生物传感器从气相到液相的稳定性非常好，并且通过检测从大肠杆菌（E.coli）中获得的内毒素，从铜绿假单胞菌中获得的内毒素，测试和验证了特异性。铜绿假单胞菌）和黄曲霉毒素。因此，这种带有 CVD 生长 SLG 膜的 SH-SAW 生物传感器可能为内毒素检测提供一种有前景的方法，并且在临床应用中可能具有巨大的潜力。