Label-Free Detection of Tobramycin in Serum by Transmission-Localized Surface Plasmon Resonance
Label-Free Detection of Tobramycin in Serum by Transmission-Localized Surface Plasmon Resonance
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DOI：
10.1021/acs.analchem.5b00389
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发表时间：
2015-05-19
影响因子：
7.4
通讯作者：
Guiducci, Carlotta
中科院分区：
文献类型：
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作者：
Cappi, Giulia;Spiga, Fabio M.;Guiducci, Carlotta
为了提高治疗的有效性和安全性，药物剂量需要根据每个患者的实际需求进行调整，以真正的个性化用药方法。广泛剂量调整的关键是能够以简单、自动化和具有成本效益的方式测量血浆药物浓度的床旁设备的可用性。在目前的工作中，我们介绍和测试一个便携式，手掌大小的传输本地化的表面等离子体共振（T-LSPR）设置，包括现成的组件和耦合的DNA为基础的适体特异性的抗生素妥布霉素（467 Da）。T-LSPR装置的核心是沉积在载玻片上的适体功能化的金纳米岛（NI），载玻片上覆盖有氟掺杂的氧化锡（FTO），其用作生物传感器。金NI在可见光范围内表现出与用作光检测器的互补金属氧化物半导体（CMOS）图像传感器的灵敏度相匹配的局部等离子体共振。FTO基底上金NI的组合导致NI尺寸和图案不规则性，可能会降低整体灵敏度，但在高离子溶液中具有极高的稳定性，使其能够承受多次再生循环而不会出现感测损失。通过这种相当简单的T-LSPR设置，我们显示了缓冲液中妥布霉素的实时无标记检测，测量浓度低至0.5 μ M。我们确定的适体-妥布霉素对的亲和常数与使用基于商业传播波的SPR获得的值一致。此外，我们的无标记系统可以检测过滤的未稀释血清中的妥布霉素，测量浓度低至10 μ M，理论检测限为3.4 μ M。虽然妥布霉素在适体上的缔合信号被血清注射掩蔽，但在解离阶段捕获的妥布霉素的定量是可能的，并导致在测试范围（10-80 μ M）内浓度的线性校准曲线。表面结合后的等离子体位移是根据等离子体峰位置和色调计算的，后者允许更快的数据细化和实时显示结果。所提出的T-LSPR系统首次显示了过滤的未稀释血清的复杂基质中的小分子的无标记直接检测和定量。其简单的结构和紧凑的尺寸，以及卓越的性能，代表了向治疗药物浓度监测的有效床旁设备的飞跃。
In order to improve the efficacy and safety of treatments, drug dosage needs to be adjusted to the actual needs of each patient in a truly personalized medicine approach. Key for widespread dosage adjustment is the availability of point-of-care devices able to measure plasma drug concentration in a simple, automated, and cost-effective fashion. In the present work, we introduce and test a portable, palm-sized transmission-localized surface plasmon resonance (T-LSPR) setup, comprised of off-the-shelf components and coupled with DNA-based aptamers specific to the antibiotic tobramycin (467 Da). The core of the T-LSPR setup are aptamer-functionalized gold nanoislands (NIs) deposited on a glass slide covered with fluorine-doped tin oxide (FTO), which acts as a biosensor. The gold NIs exhibit localized plasmon resonance in the visible range matching the sensitivity of the complementary metal oxide semiconductor (CMOS) image sensor employed as a light detector. The combination of gold NIs on the FTO substrate, causing NIs size and pattern irregularity, might reduce the overall sensitivity but confers extremely high stability in high-ionic solutions, allowing it to withstand numerous regeneration cycles without sensing losses. With this rather simple T-LSPR setup, we show real-time label-free detection of tobramycin in buffer, measuring concentrations down to 0.5 mu M. We determined an affinity constant of the aptamer-tobramycin pair consistent with the value obtained using a commercial propagating-wave based SPR. Moreover, our label-free system can detect tobramycin in filtered undiluted blood serum, measuring concentrations down to 10 mu M with a theoretical detection limit of 3.4 mu M. While the association signal of tobramycin onto the aptamer is masked by the serum injection, the quantification of the captured tobramycin is possible during the dissociation phase and leads to a linear calibration curve for the concentrations over the tested range (10-80 mu M). The plasmon shift following surface binding is calculated in terms of both plasmon peak location and hue, with the latter allowing faster data elaboration and real-time display of the results. The presented T-LSPR system shows for the first time label-free direct detection and quantification of a small molecule in the complex matrix of filtered undiluted blood serum. Its uncomplicated construction and compact size, together with the remarkable performances, represent a leap forward toward effective point-of-care devices for therapeutic drug concentration monitoring.