Department of Analytical Chemistry, Faculty of Pharmacy, Ankara Medipol University, 06050, Ankara, Turkey.
Department of Chemistry, Faculty of Science, Van Yuzuncu Yil University, 65080, Van, Turkey.
Talanta. 2022 Jan 15;237:122926. doi: 10.1016/j.talanta.2021.122926. Epub 2021 Oct 5.
Selective and sensitive detection of cancer biomarkers in serum samples is critical for early diagnosis of cancer. Prostate specific antigen is an important biomarker of prostate cancer, which ranks high among cancer-related deaths of men over 50 years old. Herein, a novel analytical method was introduced for detection of PSA by combining high selectivity of molecularly-imprinted polymers and high sensitivity of surface-enhanced Raman spectroscopy (SERS). Firstly, magnetic nanoparticles were grafted with an imprinted layer by using tannic acid as a functional monomer, diethylenetriamine as a cross-linker and prostate specific antigen as a template molecule. Detailed surface characterization and re-binding experiment results indicated that the imprinting of the antigen was successful with an imprinting factor of 5.58. The prepared magnetic molecularly imprinted polymers (MMIPs) were used as an antibody-free capture probe and labeled with gold nanoparticles that were modified with anti-PSA and a Raman reporter, namely 5,5'-dithiobis-(2-nitrobenzoic acid). Thus, a plasmonic structure (sandwich complex) was formed between MMIP and the SERS label. The limit of detection and limit of quantification of the designed sensor were 0.9 pg/mL and 3.2 pg/mL, respectively. The sensor also showed high recovery rates (98.0-100.1% for healthy person and 99.0-101.3% for patient) with low standard deviations (less than 4.3% for healthy person and less than 3.3% for patient) for PSA in serum samples. Compared with the traditional immunoassays, the proposed method has several advantages like low cost, reduced detection procedure, fast response, high sensitivity and selectivity. It is believed that the proposed method can be potentially used for selective and sensitive determination of tumor marker of prostate cancer in clinical applications.
对血清样本中癌症生物标志物进行选择性和灵敏性检测对于癌症的早期诊断至关重要。前列腺特异性抗原（PSA）是前列腺癌的重要生物标志物，在 50 岁以上男性的癌症相关死亡中排名很高。在此，我们提出了一种通过结合分子印迹聚合物的高选择性和表面增强拉曼光谱（SERS）的高灵敏度来检测 PSA 的新分析方法。首先，使用单宁酸作为功能单体、二亚乙基三胺作为交联剂、前列腺特异性抗原作为模板分子，在磁性纳米粒子上接枝印迹层。详细的表面特性和再结合实验结果表明，抗原的印迹是成功的，印迹因子为 5.58。所制备的磁性分子印迹聚合物（MMIPs）用作无抗体的捕获探针，并与经过抗 PSA 和拉曼报告分子（即 5,5'-二硫代双（2-硝基苯甲酸））修饰的金纳米粒子标记。因此，在 MMIP 和 SERS 标记物之间形成了等离子体结构（夹层复合物）。设计的传感器的检测限和定量限分别为 0.9 pg/mL 和 3.2 pg/mL。该传感器还在血清样品中对 PSA 表现出高回收率（健康人 98.0-100.1%，患者 99.0-101.3%）和低标准偏差（健康人低于 4.3%，患者低于 3.3%）。与传统的免疫测定法相比，该方法具有成本低、检测步骤少、响应快、灵敏度和选择性高等优点。相信该方法有望在临床应用中用于前列腺癌肿瘤标志物的选择性和灵敏性测定。
