传感器类型
电化学生物传感器
检测对象
抗麸质IgA自身抗体(antigliadin IgA autoantibodies)、抗麸质IgG自身抗体(antigliadin IgG autoantibodies);样品基质:乳糜泻患者血清(real serum samples)
检测原理
该传感器以金电极为换能器,表面自组装巯基化β-环糊精聚合物(CDPSH)形成亲水支撑层。金刚烷基羧甲基纤维素-麸质偶联物(ADA-CMC-GLI)通过β-CD与金刚烷(ADA)的主客体结合固定于表面,使digested gliadin抗原以多价方式呈现。血清中的抗麸质IgG/IgA与表面麸质结合后,加入相应报告抗体(文中为anti-IgG-HRP)形成免疫复合物并引入HRP。随后注入对苯二酚(HQ)和H2O2,HRP催化H2O2还原,HQ作为电子供体/介质将电子传递至金电极,在-0.2 V下产生安培电流。抗体浓度越高,表面HRP越多,电流越大;CD亲水层降低非特异吸附,多价主客体结合增强固定与响应。
检测灵敏度
LOD: 20 ng/mL;线性范围: 0–0.75 μg/mL;灵敏度斜率: 1.48 μA mL ng−1(i = 1.48[antibody] + 0.05);r = 0.991
效应效果
CDPSH/ADA-CMC-GLI体系响应最高且背景最低,对anti-CEA非特异抗体亲和力可忽略;无识别层时背景仅为饱和信号的6%。在胎牛血清中加标1 μg/mL抗麸质抗体,信号回收率接近100%,而CDPSH/ADA-GLI在纯血清中回收率为82%。安培法RSD低于6%(n=6),检测时间约40 min,显著短于ELISA的>3 h;LOD为20 ng/mL,优于ELISA的260 ng/mL。表面经SDS再生后保留>95%初始信号。真实患者血清中,传感器与商品ELISA结果高度相关且重复性好,抗麸质IgA/IgG随无麸质饮食时间下降,作者认为可用于乳糜泻筛查和饮食依从性监测。
传感器的构成
- 换能器电极:金工作电极(Au,1×1 mm²,Ti/Au 光刻),银伪参比电极(Ag)与金对电极(Au),用于安培检测
- 环糊精支撑层:巯基化β-环糊精聚合物(CDPSH)或七巯基β-环糊精(CDSH7)在金表面自组装,提供β-CD空腔并降低非特异吸附
- 识别元件层:金刚烷基羧甲基纤维素-麸质偶联物(ADA-CMC-GLI)或金刚烷基麸质(ADA-GLI),通过CD-ADA主客体结合固定digested gliadin抗原
- 识别事件:抗麸质IgG/IgA自身抗体与表面麸质结合,形成免疫复合物
- 信号标记物:鼠抗IgG-HRP偶联物(anti-IgG-HRP),结合捕获抗体并引入辣根过氧化物酶(HRP)
- 电化学介质:对苯二酚(HQ)作为电子供体/介质,过氧化氢(H2O2)作为底物,在固定电位下产生安培电流
中文摘要
乳糜泻是遗传易感个体摄入麸质后引起小肠黏膜组织学改变和吸收不良的疾病。血清抗麸质抗体检测既是诊断工具,也可用于监测患者对无麸质饮食的依从性。本文报道了一种基于环糊精修饰金表面的电化学超分子平台,用于检测真实血清样本中的抗麸质抗体。作者比较了多种支撑层与生物识别元件组合,以最大化电化学响应,并优化了孵育时间及抗非特异性相互作用条件。所开发的超分子生物传感器被用于乳糜泻患者随访治疗过程中抗麸质IgA和IgG自身抗体的安培检测,其结果与商品化酶联免疫吸附试验(ELISA)相比表现出良好相关性,表明该平台可用于乳糜泻筛查和饮食依从性监测。
英文摘要
Celiac disease is a condition associated with the ingestion of gluten by genetically susceptible individuals. Measurement of serum antigliadin antibodies is a diagnostic tool also used as a means of monitoring a patient's compliance to a gluten-free diet. In this work, we demonstrate the applicability of an electrochemical supramolecular platform based on cyclodextrin-modified gold surfaces to detect antigliadin antibodies in real serum samples. Several support layer-biorecognition element combinations were tested in order to maximize the electrochemical response, and the assay was optimized in terms of incubation times and resistance to nonspecific interactions. The developed supramolecular biosensor was then applied to the amperometric detection of antigliadin IgA and IgG autoantibodies in real samples of celiac disease patients under follow-up treatment; the results were compared with a commercial enzyme linked immunosorbent assay (ELISA) test, and an excellent correlation was observed between both methods.