以官能化二硫化鉬增強表面電漿子生醫晶片的靈敏度於新型妊娠相關血漿蛋白(PAPP-A2)在臨床血清的檢測
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2017
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表面電漿子共振生物感測器具有高靈敏度、免標記和即時檢測的特性，原理是利用光學感測生物分子結合後其相關折射率變化，進而達到分子診斷之效果。本研究提出新型感測材料，以二硫化鉬為基材進行表面改質修飾羧基(-COOH)，以提升生物間的親和力(affinity)，及增強界面的功函數(work function)與電場傳播特性進而提升檢測靈敏度。
本研究使用兩種方式製備官能化二硫化鉬晶片，分別為將草酸(Oxalic)及氯乙酸(MCA)兩種有機酸的羧基(-COOH)修飾至二硫化鉬表面，進行感測材料的優質化比較。其中氯乙酸修飾技術，主要是以氯原子佔據硫空缺，有較高的穩定性及結合率，有別於傳統的方法以硫醇直接吸附於硫空缺。利用XPS、FTIR、TEM、UPS和Zeta potential等方式成功證實羧基修飾至二硫化鉬表面，且於XPS的分析結果顯示，羧基在碳原素的含量佔24.4%，在氧原素中佔28.2%。在生物檢測方面，提出低注入量(20 μL)和低流速(6 μL/min)於牛血清白蛋白免疫法實驗，進行與傳統SPR晶片靈敏度比較，在氯乙酸修飾的官能化二硫化鉬晶片靈敏度提升2.35倍。在PAPP-A2重組蛋白的實驗，迴歸係數達到R2=0.99，而加入干擾物後並不影響靈敏度與線性值。於檢測臨床血清樣本之新型妊娠相關血漿蛋白(PAPP-A2)的實驗，將檢體稀釋至40,000倍(0.05 pg/mL)，仍可檢測到共振角位移量為0.96 mo，且線性迴歸係數可達到R2=0.958。
由此可證明本研究開發的官能化二硫化鉬感測晶片具有高靈敏度及高親和性之優勢，且PAPP-A2擁有高的專一性，有潛力成為未來在妊娠疾病診斷的新型指標蛋白，有望成為唐氏症之篩檢蛋白，可達成快速篩檢及高檢出率之目標。
The advantages of surface plasmon resonance (SPR) biosensor includes high sensitivity, lable-free and real-time monitoring. The principle is the use of optical sensing interfacial refractive index changes associated with any affinity binding interaction between a biomolecule immobilized on a sensor surface. In this study, we propse a new sensing material, which modified the carboxyl acid groups (-COOH) with molybdenum disulfide (MoS2) to enhance the bio-interaction affinity, the work function and electric field propagation characteristics. Thereby improving the detection sensitivity. In this study, functionalized MoS2 chips (f-MoS2 chip) were prepared in two ways. The carboxyl acid groups (-COOH) of oxalic and chloroacetic acid (MCA) were modified to the surface of MoS2 to carry out the quality of the sensing material comparison. Which MCA modification technology, mainly chlorine atoms occupy sulfur vacancies, have a high stability and binding efficiency, different from the traditional method of thiol ligand modifications, in this instance, they yield physisorbed disulfides that are easily removed. The results of XPS analysis showed the content of carboxyl group was 24.4% in C1s and 28.2% in O1s, and f-MoS2 was confirmed by XPS, FTIR, TEM, TEM, UPS and Zeta potential. In the biological detection, low injection (20 μL) and low flow rate (6 μL / min) in bovine serum albumin (BSA) immunoaffinity detection were carried out to compare with traditional SPR chip sensitivity in the presence of f-MoS2 (MCA) chip sensitivity increased by 2.35 times. In the PAPP-A2 recombinant protein experiment, the R2=0.99, and after adding the interference does not affect the sensitivity and linearity. PAPP-A2 in clinical serum samples, the sample was diluted to 40000 times, and the SPR angle of PAPP-A2 at a concentration of about 0.05 pg/mL could still be detected, R2 = 0.958. We demonstrated that f-MoS2 chip has high sensitivity in the detection of clinical samples. PAPP-A2 has a high specificity and has the potential to become a new indicator protein for future diagnosis of pregnancy disorders, which is expected to be a screening protein for Down's syndrome, achieving rapid screening and high detection rates in the future.
The advantages of surface plasmon resonance (SPR) biosensor includes high sensitivity, lable-free and real-time monitoring. The principle is the use of optical sensing interfacial refractive index changes associated with any affinity binding interaction between a biomolecule immobilized on a sensor surface. In this study, we propse a new sensing material, which modified the carboxyl acid groups (-COOH) with molybdenum disulfide (MoS2) to enhance the bio-interaction affinity, the work function and electric field propagation characteristics. Thereby improving the detection sensitivity. In this study, functionalized MoS2 chips (f-MoS2 chip) were prepared in two ways. The carboxyl acid groups (-COOH) of oxalic and chloroacetic acid (MCA) were modified to the surface of MoS2 to carry out the quality of the sensing material comparison. Which MCA modification technology, mainly chlorine atoms occupy sulfur vacancies, have a high stability and binding efficiency, different from the traditional method of thiol ligand modifications, in this instance, they yield physisorbed disulfides that are easily removed. The results of XPS analysis showed the content of carboxyl group was 24.4% in C1s and 28.2% in O1s, and f-MoS2 was confirmed by XPS, FTIR, TEM, TEM, UPS and Zeta potential. In the biological detection, low injection (20 μL) and low flow rate (6 μL / min) in bovine serum albumin (BSA) immunoaffinity detection were carried out to compare with traditional SPR chip sensitivity in the presence of f-MoS2 (MCA) chip sensitivity increased by 2.35 times. In the PAPP-A2 recombinant protein experiment, the R2=0.99, and after adding the interference does not affect the sensitivity and linearity. PAPP-A2 in clinical serum samples, the sample was diluted to 40000 times, and the SPR angle of PAPP-A2 at a concentration of about 0.05 pg/mL could still be detected, R2 = 0.958. We demonstrated that f-MoS2 chip has high sensitivity in the detection of clinical samples. PAPP-A2 has a high specificity and has the potential to become a new indicator protein for future diagnosis of pregnancy disorders, which is expected to be a screening protein for Down's syndrome, achieving rapid screening and high detection rates in the future.
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表面電漿子共振, 生物感測器, 官能化二硫化鉬, 姙娠相關血漿 蛋白A2, Surface plasmon resonance, Biosensor, Functionalized MoS2, PAPP-A2