Demonstration of sandwich and competitive modulated supraparticle fluoroimmunoassay applied to cardiac protein biomarker myoglobin
Demonstration of sandwich and competitive modulated supraparticle fluoroimmunoassay applied to cardiac protein biomarker myoglobin
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DOI：
10.1039/b809665a
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发表时间：
2009-01-01
期刊：
影响因子：
4.2
通讯作者：
Mahanti, Prasun
中科院分区：
文献类型：
--
作者：
Hayes, Mark A.;Petkus, Matthew M.;Mahanti, Prasun
调制超微粒结构用于改善夹心和竞争性荧光免疫测定。改进的方法在肌红蛋白上得到了证明，肌红蛋白是检测心脏损伤的关键诊断蛋白。所得到的方法使用微升体积的牛血清样品掺杂不同浓度的马肌红蛋白。这些免疫测定使用微米直径的氧化铁颗粒作为抗体锚定的固相。磁场的引入在粒子上产生了偶极矩，这将它们彼此吸引以形成棒状超粒子结构。这些结构可以在交变磁场内旋转，产生对流和周期性信号，可以用锁定放大进行分析，从而实现更灵敏的检测。该系统在与急性心肌梗死（AMI）相关的目标上进行了演示。这种疾病导致心脏供氧减少，导致组织死亡和心肌红蛋白释放到血液中。研究表明，对血清肌红蛋白浓度的评估和监测在早期诊断AMI时是重要的。早期诊断至关重要，因为在症状出现的前两个小时内进行治疗是最有效的。调制的测定是快速，准确，灵敏度为肌红蛋白的小体积血清样品的评估。使用5.0 nM的临界值（85 ng/mL）用于AMI诱导的肌红蛋白，调制的竞争性测定能够在仅10分钟的孵育时间后诊断掺杂有肌红蛋白的血清中的AMI样条件。调制的夹心测定的标准曲线在0至1 nM的范围内是线性的（17 ng/mL），检测下限为50 pM（0.85 ng/mL）。
Modulated supraparticle structures are used to improve sandwich and competitive fluoroimmunoassays. The improved methods are demonstrated on myoglobin, a key diagnostic protein for detection of heart damage. The resulting method uses microliter volumes with bovine serum samples doped with varying concentrations of equine myoglobin. These immunoassays use micron-diameter iron oxide particles as a solid phase for antibody anchoring. Introduction of a magnetic field creates dipole moments on the particles, which attracts them to each other to form rod-like supraparticle structures. These structures can rotate within an alternating magnetic field generating convective flow and a periodic signal that can be analyzed with lock-in amplification enabling more sensitive detection. The system is demonstrated on a target associated with acute myocardial infarction (AMI). This disease causes decreased oxygen delivery to the heart resulting in tissue death and the release of cardiac myoglobin into the bloodstream. Studies have shown that the assessment and monitoring of serum myoglobin concentrations is important when making an early diagnosis of AMI. Early diagnosis is crucial since treatment is most effective when done within the first two hours of symptoms. The modulated assay is rapid, accurate, and sensitive for myoglobin assessment of small-volume serum samples. Using a cut-off value of 5.0 nM (85 ng/mL) for AMI induced myoglobin, the modulated competitive assay was able to diagnose AMI-like conditions in serum doped with myoglobin after an incubation time of only 10 min. The standard curve developed for the modulated sandwich assay was linear over a range of zero to 1 nM (17 ng/mL) with a lower limit of detection at 50 pM (0.85 ng/mL).