PNAS：可能的便携式床边诊断平台
科研人员制造了一种便携式床边诊断设备的原型，它对于多种生物靶标具有改良的探测范围和灵敏度。许多生物医学诊断设备有缺点，包括长的样本处理和分析时间，狭窄的动态探测范围，以及缺乏便携性。Ronald Davis及其同事开发了一种称为纳米等离子电场增强共振设备(NE2RD)的诊断平台，它含有一个金纳米颗粒包覆的聚苯乙烯表面，其上固定了诸如抗体等反应试剂。在各种温度、pH值和离子强度条件下，这种设备在诸如血液、血清和唾液的临床样本小滴中探测到了一批生物靶标，包括蛋白质、病毒、细菌和药物，常常不需要进行标记。通过追踪纳米颗粒的振荡，具有大约8个数量级的线性动态范围的NE2RD可靠地探测到了400 fg/ml 的免疫分子IFN-γ，而标准的诊断分析方法elisa的检测限度是大约25 pg/ml。对病人血清和唾液中的1型艾滋病病毒和常见的共同感染——卡波西肉瘤相关疱疹病毒水平的测量数据不仅与通过现有的基于PCR的技术获得的数据一致，而且还表明了病人对治疗的应答，这提示了这种装置的临床有效性。此外，这组作者将NE2RD集成到了一种一次性的便携式流式芯片中，而没有显著减少探测灵敏度。这组作者说，NE2RD可能代表了一种便携式床边诊断装置的原型。原文链接：
Multitarget, quantitative nanoplasmonic electrical field-enhanced resonating devICE (NE2RD) for diagnostics
原文摘要：
Recent advances in biosensing technologies present great potential for medical diagnostics, thus improving clinical decisions. However, creating a label-free general sensing platform capable of detecting multiple biotargets in various clinical specimens over a wide dynamic range, without lengthy sample-processing steps, remains a considerable challenge. In practice, these barriers prevent broad applications in clinics and at patients’ homes. Here, we demonstrate the nanoplasmonic electrical field-enhanced resonating device (NE2RD), which addresses all these impediments on a single platform. The NE2RD employs an immunodetection assay to capture biotargets, and precisely measures spectral color changes by their wavelength and extinction intensity shifts in nanoparticles without prior sample labeling or preprocessing. We present through multiple examples, a label-free, quantitative, portable, multitarget platform by rapidly detecting various protein biomarkers, drugs, protein allergens, bacteria, eukaryotic cells, and distinct viruses. The linear dynamic range of NE2RD is five orders of magnitude broader than ELISA, with a sensitivity down to 400 fg/mL This range and sensitivity are achieved by self-assembling gold nanoparticles to generate hot spots on a 3D-oriented substrate for ultrasensitive measurements. We demonstrate that this precise platform handles multiple clinical samples such as whole blood, serum, and saliva without sample preprocessing under diverse conditions of temperature, pH, and ionic strength. The NE2RD’s broad dynamic range, detection limit, and portability integrated with a disposable fluidic chip have broad applications, potentially enabling the transition toward precision medicine at the point-of-care or primary care settings and at patients’ homes.
doi: 10.1073/PNAS.1510824112
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