電化學(xué)傳感器論文：基于電活性納米復(fù)合材料構(gòu)建生物傳感的研究

1、電化學(xué)傳感器論文：基于電活性納米復(fù)合材料構(gòu)建生物傳感的研究【中文摘要】生物傳感器是目前極為活躍的研究領(lǐng)域,而其中電化學(xué)傳感器因具有好的選擇性、高靈敏度、低成本、分析速度快、操作簡單、易于微型化等優(yōu)點,在環(huán)境監(jiān)測、食品和醫(yī)藥工業(yè)、臨床診斷等領(lǐng)域有著重要的應(yīng)用價值。在電化學(xué)生物傳感器的研制中,因納米性材料擁有很多優(yōu)點,比如它具有優(yōu)越的導(dǎo)電能力、其良好的催化特性及其生物的相容性比較好,所以研究其在電化學(xué)傳感器中的應(yīng)用,對于提出新理論和新方法,構(gòu)造新型、簡單的電分析生命傳感器具有非常重要的實際意義。同時構(gòu)建納米-生物傳感界面,將納米功能材料與生物功能分子的特殊性質(zhì)及性能相結(jié)合,發(fā)揮材料間的協(xié)同效應(yīng),有

2、助于加快生物傳感器的發(fā)展。本文以納米和納米-生物傳感界面的構(gòu)建,以及在電化學(xué)傳感器中的應(yīng)用為主旨,期間具體開展的研究工作如下：1.本文通過戊二醛將殼聚糖(CHIT)和電子介體甲苯胺藍(TB)進行交聯(lián),得到的CHIT-TB復(fù)合物修飾在金電極(Au)表面,靠靜電作用吸附金納米粒子(AuNPs)。再利用納米金材料良好的生物兼容性、大的比表面積固定乙肝表面抗體(HBsAb),從而可進一步對乙肝表面抗原進行檢測。構(gòu)建的CHIT-TB/Au NPs/HBsAb/BSA免疫傳感器兼具以下優(yōu)點：CHIT在此不僅可以提供一個良好的生物微環(huán)境,同時它通過戊二醛交聯(lián),將TB共價鍵合上去,解決了電子介體易泄漏問題,提

3、高電極的穩(wěn)定性。Au NPs具有良好的導(dǎo)電性和大的比表面積,對于構(gòu)建的傳感器能起到放大信號作用,能提高該傳感器的靈敏度。實驗過程中采用微分脈沖伏安法(DPV),對HBsAg進行定量檢測。檢測的HBsAg的濃度范圍在1-200 ng mL-1,檢測限為0.28 ng mL-1。該方法檢測范圍寬、檢測限低,從而為肝炎的早期診斷提供了一個方便,快捷,且低成本的方法。2.介紹一種靈敏檢測癌癥標記物-甲胎蛋白(AFP)的新型電化學(xué)免疫傳感器,這種傳感器用石墨烯作為一個傳感平臺,金納米粒子(Au NPs)用于固定a-甲胎蛋白抗體(anti-AFP)。首先,化學(xué)【英文摘要】Biosensor is a ve

4、ry active research and engineering technical field. Wherein, electrochemical biosensors have valuable applications in clinical diagnosis, environmental monitoring, food and pharmacy industries because of its excellent selectivity, high sensitivity, rapid response, low cost, continuous detection, eas

5、y to be miniaturized. In the design and fabrication of electrochemical biosensors, given the characteristics of nano-materials such as the ability of facilitating electron transfer rate, catalytic performance, absorbability, application of nano-materials in bio-electroanalysis plays a meaningful rol

6、e, in terms of proposing new detection principles and new detection methods/techniques, as well as developing novel yet sensitive electrochemical biosensors. Construction of nanobio-interface, incorporating the distinctive features of nano-materials and biomolecules to exert a synergistic effect, co

7、ntributes a lot to the development of biosensors. With emphasis on the contruction of nano-films and nano-biomolecule composite interfaces, as well as their application in electrochemical biosensors, this article has carried out the following works:1. A novel amperometric immunosensor has been devel

8、oped by self-assembling gold nanoparticles (Au NPs) onto a toluidine blue-branched chitosan (CHIT-TB) modified electrode for the sensitive determination of hepatitis B surface antigen (HBsAg) as a model protein. The formation of CHIT-TB composite film not only effectively avoids the leakage of TB an

9、d retains its electrochemical activity, but also enhances the conductivity and charge-transport properties of the composite. Further adsorption of Au NPs into the CHIT matrix provides both the interactive sites for the immobilization of HBsAb and a favorable microenvironment to maintain the activity

10、 of the HBsAb, in addition prevents leakage of HBsAb molecules from the CHIT-TB/Au NPs/HBsAb film structure efficiently. The morphologies and electrochemistry of the formed nanocomposite film were investigated by using scanning electron microscopy and electrochemical techniques including cyclic volt

11、ammetry and electrochemical impedance spectroscopy. The HBsAg concentration was measured through the decrease of amperometric responses in the corresponding specific binding of antigen and antibody. The decreased voltametric values were proportional to the HBsAg concentration in the range of 1 to 20

12、0 ng mL-1. The detection of HBsAg levels in five sera obtained from hospital showed acceptable accuracy.2. A novel electrochemical immunosensor for sensitive detection of cancer biomarker-fetoprotein (AFP) is described that uses a graphene sheet sensor platform and gold nanoparticles (Au NPs) for im

13、mobilization of-fetoprotein antibody (anti-AFP). Greatly enhanced sensitivity for the cancer biomarker is based on a dual signal amplification strategy:First, chemically reduced graphene (CRG) functionalized with TB (CRG-TB) is well-dispersed into water through the coulomb repulsion between TB-adsor

14、bed CRG sheets. Meanwhile, functionalized graphene sheets used for the biosensor platform increased the surface area to capture a large amount of antibodies, thus amplifying the detection response. Second, good biocompatibility of Au NPs, which enhances the antibody absorption and promotes electron

15、transfer between redox mediator and the surface of electrode could maintain antibody activity. Therefore a novel and simple electrochemical immunosensor for the ultrasensitive detection of AFP was developed. The developed immunosensor showed a wide linear ranges (0.1-200 ng mL-1) and low detection l

16、imits (0.04 ng mL-1). The proposed method showed good precision, high sensitivity, acceptable stability and reproducibility, and could be used as a convenient and cost-effectively tool for hepatitis diagnosis at early stage.3. A new electrochemical immunoassay protocol for sensitive detection of-fet

17、oprotein (AFP, as a model) is designed using graphene sheet (CRG) to immobilize mediator toluidine blue (TB)-functionalized biomimetic interface as immunosensing probe and Fe3O4Au labeled horseradish peroxidase-anti-AFP conjugates (HRP-anti-AFP-Fe3O4Au) as trace label. The thionine functionalized gr

18、aphene sheets used for the biosensor platform increased the surface area to capture a large amount of primary antibodies (Ab1), thus amplifying the detection response. Moreover, the low-toxic and high-conductive Fe3O4Au provided a high capacity nanoparticulate immobilization surface and a facile pat

19、hway for electron transfer. The immunosensor displayed a wide range of linear response (1-25 pg mL-1), low detection limit (0.31 pg mL-1), good reproducibility, selectivity and stability. The good performance of the immunosensor is attributed to the graphene sheets high surface-to-volume ratio which

20、 allows the immobilization of a high-level of Ab1, Ab2, Thi and HRP and its good electrical conductivity which can improve the electron transfer among TB, HRP, H2O2 and electrode. The immunosensor was used to detect the AFP contents in serum samples from patients and satisfactory test results were o

21、btained in comparison with the ELIS A test results. Thus, graphene-based labels may provide many potential applications for the detection of different cancer biomarkers.4. A hydrogen peroxide sensor based on the glass carbon electrode modified with the thionine-graphene/gold nanoparticle nanocomposi

22、te (CRG-Thi/Au NPs/GCE) was fabricated. The applied potential was-0.3V, and the linearity range was from 0.002 to 0.7 mmol L-1 with a detetion limit of 0.64mol L-1, the experimental results demonstrate that the fabricated sensor was more sensitive for the H2O2 determination compared with CRG/GCE and

23、 CRG-Thi/GCE.【關(guān)鍵詞】電化學(xué)傳感器 甲苯胺藍 硫堇 石墨烯 金納米粒子 電催化 過氧化氫傳感器【英文關(guān)鍵詞】biosensors, nanocomposite graphene gold nanoparticle toluidine blue thionine electrocatalysis hydrogen peroxide sensor【目錄】基于電活性納米復(fù)合材料構(gòu)建生物傳感的研究摘要3-5ABSTRACT5-7第1章 緒論11-281.1 生物傳感器11-151.1.1 生物傳感器概況簡介111.1.2 生物傳感器的原理11-151.1.3 生物傳感器的分類151.2

24、免疫傳感器簡介15-181.2.1 免疫傳感器的定義15-161.2.2 免疫傳感器的工作原理161.2.3 免疫傳感器的分類161.2.4 電化學(xué)免疫傳感器16-181.3 酶傳感器18-191.4 納米材料在化學(xué)/生物分析及傳感中的應(yīng)用19-221.4.1 金納米粒子在生物醫(yī)學(xué)工程中的應(yīng)用20-211.4.2 石墨烯在傳感器中的應(yīng)用21-221.5 總結(jié)與前景展望22-23參考文獻23-28第2章 甲苯胺藍-殼聚糖納米復(fù)合物的制備及其在生物傳感器構(gòu)建中的應(yīng)用28-422.1 引言28-292.2 實驗部分29-312.2.1 試劑與儀器292.2.2 實驗方法29-312.3 結(jié)果與討論3

25、1-382.3.1 CHIT-TB復(fù)合材料的紅外光譜表征31-322.3.2 不同修飾膜的表面形貌表征32-332.3.3 電極修飾過程的電化學(xué)表征33-352.3.4 實驗條件的優(yōu)化35-362.3.5 免疫傳感器的安培響應(yīng)36-372.3.6 免疫傳感器的重現(xiàn)性,穩(wěn)定性和特異性372.3.7 樣品測定37-382.4 結(jié)論38-39參考文獻39-42第3章 甲苯胺藍功能化石墨烯免疫傳感器的構(gòu)建及其甲胎蛋白檢測應(yīng)用42-523.1 引言42-433.2 實驗43-443.2.1 試劑433.2.2 儀器43-443.2.3 石墨烯/甲苯胺藍復(fù)合材料的制備(CRG-TB)443.2.4 制備免疫傳感器443.3 結(jié)果與討論44-493.3.1 石墨烯及其復(fù)合材料的電鏡表征44-453.3.2 CRG-TB的光譜表征45-463.3.3 修飾電極的循環(huán)伏安特性463.3.4 修飾電