基于生物合成纳米材料的肿瘤生物标志物免疫分析

Cancer presents a major threat to global health since the lack of early detection and access to treatment. It is crucial to develop high-quality screening and early detection techniques for improving survival rates. Recently, the application of nanotechnology to cancer diagnosis holds great promise in improving the techniques. Some nanoparticle probes exhibit unique properties that are superior in cancer detection. For example, the large surface area of particles enables dense coverage of the surface with targeting moieties. For a typical design of biomarker detection is a sandwich-type assay. To get nanoparticle probes, it usually requires synthesis of nanoparticles using traditional methods and conjugation of the particle with secondary antibody. However, this process is rather time-consuming and labor-intensive. Another issue in immunoassay is the lack of sensitivity and selectively to diagnose many types of cancer markers. Moreover, many assays shows slow antibody-antigen binding kinetics and long assay time at low target level. To overcome these limitations, development of highly sensitive, selective, simple and rapid immunoassay approaches using nanoparticle probes has attracted great interest.. Biosynthesis of nanoparticle is an environmentally friendly, simple and efficient approach. Nanoparticles such as gold nanoparticles and quantum dots have been prepared using various organisms such as Staphylococcus aureus. These nanoparticles offer potential functional groups for convenient binding of targeting moieties for use in the diagnosis. For example, the protein A expressed on the surface of Staphylococcus aureus specifically interacts with the Fc region of antibodies against targets of interest, which is advantageous for use in immunoassay. This research will focus on development of biosensors for immunoassay of caner markers based on biosynthesized nanoparticles: (1) Modify electrode with biosynthesized quantum dots and prepare electrochemical and electrocheminescent immunosensors for prostate cancer marker and hepatocellular carcinoma marker assay. (2) Assembly of biosynthesized nanoprobes and nanoparticles to build amplified and rapid detection platforms. (3) Prepare functional nanoprobes for high-throughput analysis of cancer biomarkers.

纳米技术的发展为肿瘤的早期诊断注入新的活力,纳米探针在肿瘤标志物检测中具有优势。然而，基于纳米探针的免疫方法需要先制备纳米材料，然后在其表面修饰识别物质得到探针，耗时费力。另外，在对多种肿瘤疾病分析时方法灵敏度及选择性欠佳，抗原-抗体结合的动力学过程较慢导致对低浓度靶标检测时分析时间过长。构建新型纳米探针，发展高灵敏、高特异性、响应快速的免疫分析方法非常必要。. 我们基于绿色、温和的生物合成方法，制备新型纳米材料用于肿瘤标志物的免疫分析。主要包括（1）设计基于生物合成的纳米探针，构建电化学、电化学发光及荧光免疫传感器，对生物标志物如肝癌及前列腺癌肿瘤标志物进行检测。（2）组装纳米粒子与生物探针，实现灵敏快捷的可视化及荧光、电化学检测。（3）制备新型功能材料，进行多通量免疫分析。

纳米探针由于其优越的性能，已经广泛应用于免疫传感器的构建,用来检测肿瘤标志物。然而，传统的纳米材料及探针合成涉及苛刻的反应条件如高温高压，一些反应需要强还原剂或环境不友好的有毒试剂，并且反应大多难以控制。此外，免疫传感器构建过程中，酶或抗体偶连到纳米颗粒表面的方法大多复杂且耗时。因此，构建新型纳米探针，制备传感方法便利、检测灵敏的免疫技术非常必要。.在该课题中，基于绿色，温和的生物合成方法，我们设计合成了一系列新型纳米材料与组装结构，建立了灵敏便利的免疫分析方法，用于多种肿瘤标志物的检测。(1) 制备了基于金葡菌的半导体量子点纳米探针，建立了电化学及电致化学发光免疫检测新方法. (2) 构建了基于酶促金纳米星晶体生长的可视化及光热双重免疫检测新方法。(3)基于生物大分子DNA自组装结合级联信号扩增技术，设计DNA组装体及纳米结构，建立了多种信号放大的肿瘤标志物检测技术。以上策略均实现了肿瘤标志物的超灵敏及特异性检测。例如，对前列腺肿瘤标志物检测限低至pM水平，并可用于临床病人复杂血清样品的检测分析。基于生物合成设计的纳米探针拓宽了纳米材料在生物医学中的应用，为分析检测与成像提供了便利的工具，从而在临床诊断和治疗领域具有广阔的前景。