Yadav Amit K, Verma Damini, Solanki Pratima R
Nano-Bio Laboratory, Special Centre for Nanoscience, Jawaharlal Nehru University, New Delhi-110067, India.
J Mater Chem B. 2025 Aug 20;13(33):10187-10205. doi: 10.1039/d5tb00741k.
Sperm protein-17, also known as Sp17, is a testis-linked cancerous antigen found in various cancers, making it a potential biomarker for cancer detection. However, detecting Sp17 in human serum is challenging due to its low concentration and the absence of sensitive, specific detection methods. This study presents a fast, accurate, reliable, and cost-effective biosensor for Sp17 detection, utilizing a disposable carbon cloth (CC)-based electrode modified with a ternary nanosystem of molybdenum disulfide (MoS), reduced graphene oxide (rGO), and multi-walled carbon nanotubes (MWCNTs). The ternary nanosystem was prepared through a simple hydrothermal approach and characterized using various techniques, including X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, and electrochemical studies, which confirmed its robust formation and suitability for Sp17 sensing. The nanosystem exhibited electrocatalytic activity, biocompatibility, and stability. A Sp17-specific antibody (anti-Sp17) was attached to the surface of the electrode, and the immunosensor showed a linearity range from 0.01 to 11 ng mL with a detection limit (LOD) of 0.23 ng mL as well as a limit of quantification (LOQ) of 0.79 ng mL, achieving a sensitivity of 9.97 μA ng mL cm. The mechanism behind the sensing is attributed to charge transfer-induced shifts in the Fermi level, causing band bending at the interface between the nanosystem and the target molecule, leading to enhanced sensitivity. The theoretical analysis correlates these Fermi energy shifts with device sensitivity, particularly with antibody immobilization. The immunosensor was successfully used to detect Sp17 in human serum samples, showing good accuracy, reproducibility, and selectivity. It also correlated with a commercial enzyme-linked immunosorbent assay (ELISA), suggesting its potential for clinical diagnostics, particularly for ovarian and other Sp17-related cancers.
精子蛋白17，也称为Sp17，是一种与睾丸相关的癌抗原，在多种癌症中都能发现，这使其成为癌症检测的潜在生物标志物。然而，由于其在人血清中的浓度较低且缺乏灵敏、特异的检测方法，检测Sp17具有挑战性。本研究提出了一种用于Sp17检测的快速、准确、可靠且经济高效的生物传感器，该传感器利用了一种基于一次性碳布（CC）的电极，该电极用二硫化钼（MoS）、还原氧化石墨烯（rGO）和多壁碳纳米管（MWCNTs）的三元纳米系统进行了修饰。通过简单的水热法制备了三元纳米系统，并使用包括X射线衍射、透射电子显微镜、扫描电子显微镜、拉曼光谱和电化学研究在内的各种技术对其进行了表征，这些研究证实了其稳定形成以及对Sp17传感的适用性。该纳米系统表现出电催化活性、生物相容性和稳定性。将Sp17特异性抗体（抗Sp17）附着在电极表面，该免疫传感器的线性范围为0.01至11 ng/mL，检测限（LOD）为0.23 ng/mL，定量限（LOQ）为0.79 ng/mL，灵敏度达到9.97 μA ng/mL cm。传感背后的机制归因于电荷转移引起的费米能级移动，导致纳米系统与目标分子之间的界面处出现能带弯曲，从而提高了灵敏度。理论分析将这些费米能移动与器件灵敏度相关联，特别是与抗体固定化相关联。该免疫传感器成功用于检测人血清样品中的Sp17，显示出良好的准确性、重现性和选择性。它还与商业酶联免疫吸附测定（ELISA）相关，表明其在临床诊断中的潜力，特别是对于卵巢癌和其他与Sp17相关的癌症。
