Qiang Liangliang, Vaddiraju Santhisagar, Patel Dipesh, Papadimitrakopoulos Fotios
Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269, United States.
Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269, United States; Biorasis Inc., 23 Fellen Road, Storrs, CT 06268, United States.
Biosens Bioelectron. 2011 May 15;26(9):3755-60. doi: 10.1016/j.bios.2011.02.021. Epub 2011 Feb 18.
The promise of implantable electrochemical sensors is often undermined by the critical requirement of device miniaturization that inadvertently degrades sensor performance in terms of sensitivity and selectivity. Herein, we report a novel miniaturized and flexible amperometric sensor grown at the 'edge plane' of a 25-μm gold wire. Such geometry affords extreme miniaturization along with ease of fabrication, minimal iR drop and 3-D diffusion for effective mass transfer. This together with electrochemical rebuilding of the Au working electrode and subsequent Pt nanoparticles deposition resulted in the highest H2O2 sensitivity (33 mA mM(-1) cm(-2)), reported thus far. Concurrent electrodeposition of o-phenylenediamine with glucose oxidase afforded glucose detection at these edge-plane microsensors with a six fold improvement in sensitivity (1.2 mA mM(-1) cm(-2)) over previous reports. In addition, these sensors exhibit low operation potential (0.3 V), high selectivity (more than 95%) against in vivo interferences, and an apparent Michealis-Menten constant (K(m)(app)) of 17 and 75 mM of glucose in the absence and presence of an outer polyurethane coating, respectively. These features render the edge-plane sensor architecture as a powerful platform for next-generation implantable biosensors.
可植入式电化学传感器的前景常常因器件小型化这一关键要求而受到影响，该要求无意间会在灵敏度和选择性方面降低传感器性能。在此，我们报告一种在25μm金线的“边缘平面”生长的新型小型化且柔性的安培传感器。这种几何结构实现了极高的小型化，同时具备易于制造、最小的iR降以及有效传质的三维扩散。这与金工作电极的电化学重建以及随后铂纳米颗粒的沉积相结合，产生了迄今为止报道的最高的H2O2灵敏度（33 mA mM(-1) cm(-2)）。邻苯二胺与葡萄糖氧化酶的同时电沉积使得在这些边缘平面微传感器上能够检测葡萄糖，其灵敏度比之前的报道提高了六倍（1.2 mA mM(-1) cm(-2)）。此外，这些传感器具有低工作电位（0.3 V）、对体内干扰的高选择性（超过95%），并且在不存在和存在外部聚氨酯涂层的情况下，葡萄糖的表观米氏常数（K(m)(app)）分别为17 mM和75 mM。这些特性使边缘平面传感器架构成为下一代可植入生物传感器的强大平台。
