Speed and sensitivity - Integration of electrokinetic preconcentration with a leaky waveguide biosensor
Speed and sensitivity - Integration of electrokinetic preconcentration with a leaky waveguide biosensor
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DOI：
10.1016/j.snb.2019.127063
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发表时间：
2019-12-12
影响因子：
8.4
通讯作者：
Gupta, Ruchi
中科院分区：
文献类型：
--
作者：
Goddard, Nicholas J.;Gupta, Ruchi
通过预浓缩提高检测极限和缩短光学生物传感器的响应时间是使其能够在护理点(POC)应用中使用的关键要求。为了满足这些要求，我们已经证明，将pH步等电聚焦与含有非特异性亲和配体(活性蓝4染料)的漏波(LW)传感器相结合，可以将样本蛋白质(牛血清白蛋白)的检测极限降低600-930倍，并缩短对<；60 S的响应时间。这是以前报道的6-9倍的预浓缩和高达16倍的响应时间。等电色谱用标准的两性离子液体和简单的酸和碱形成一个pH阶梯。使用两性离子有很好的预浓缩效果，但比使用pH步骤要慢得多。LW传感器使用了一层薄的琼脂糖水凝胶层，其中固定了RB4。该染料既是一种非特异性亲和配体，也是一种可视化的波导谐振。这使得可以在沿10 mm分离通道长度的任何点实时监测波导的折射率。
Improving the limit of detection by preconcentration and reducing the response time of optical biosensors are key requirements to enable their use in point of care (P0C) applications. To address these requirements, we have shown that integration of isoelectric focusing (IEF) at a pH step with a leaky waveguide (LW) sensor containing a non-specific affinity ligand (reactive blue 4 dye (RB4)) can reduce the limit of detection of an exemplar protein (bovine serum albumin (BSA)) by a factor of 600-930 and reduce the response time to < 60 s. This is 6-9 times better preconcentration and up to 16 times faster response time than previous reports. IEF was performed with standard ampholytes and with simple acids and bases forming a pH step. Using ampholytes gave good preconcentration, but was much slower than using a pH step. The LW sensor used a thin agarose hydrogel layer into which RB4 was immobilized. The dye acted both as a non-specific affinity ligand and to visualize the waveguide resonances. This allowed the refractive index of the waveguide to be monitored in real time at any point along the 10 mm separation channel length.