Silicon nanowires to detect electric signals from living cells

Abstract

The ability to merge electronic devices with biological systems at the cellular scale is an interesting perspective. Potential applications span from investigating the bio-electric signals in excitable (and non-excitable) cells with an insofar-unreached resolution to plan next-generation therapeutic devices. Semiconductor nanowires (NWs) are well suited for achieving this goal because of their intrinsic size and wide range of possible configurations. However, production of such nanoscale electrodes is pricey, time-consuming and affected by poor compatibility with the Complementary Metal-Oxide-Semiconductor integrated circuits (CMOS-IC) process standards. To take a step forward, we introduced a new method to fabricate small, high-density Silicon NWs (SiNWs) with a fast, relatively inexpensive and low-temperature (200 °C) process. Growth of such SiNWs is compatible with CMOS-IC standards, thus theoretically allowing on-site amplification of bioelectric signals from living cells in tight contact. Here, we report our preliminary data showing the biocompatibility of such SiNWs, as a necessary step to produce a compact device providing super-resolved descriptions of bioelectric waveforms captured from the subcellular to the network level.

Biocompatibility and Connectivity of Semiconductor Nanostructures for Cardiac Tissue Engineering Applications

“…For each sample, three images were collected in different sites and analyzed, and a total of 30 measurements were used for the evaluation of average length. Methods for the preparation of Si nanowires have been thoroughly described previously [ 22 ].…”

Etching rate of silicon nanowires with highly doped silicon during metal-assisted chemical etching

“…As a simple process allowing large-area fabrication, metal-assisted chemical etching to fabricate SiNWs has been widely applied in the field of solar cells [1][2][3][4][5], thermoelectric [6][7][8][9][10], biology [11][12][13][14][15], and sensors [16][17][18][19][20]. To understand the etching characteristics of silicon with different doped concentration is significant for controlling the fabrication for various applications.…”

Preparation of Silicon Nanowires and Porous Silicon Composite Structure by Electrocatalytic Metal Assisted Chemical Etching

“…硅纳米线(Silicon Nanowires-SiNWs)结构自问 世以来，与体硅材料相比表现出优异的电学和光学 特性，在生物系统 [1] 、热电子器件 [2][3] 和太阳能电池 [4][5] 等领域表现出巨大的应用潜力。 SiNWs 拉曼光谱 不对称加宽和拉曼红移表明尺寸足够小时，SiNWs 存在量子限制效应，电子的运动在另外两个维度受 到限制， 使 SiNWs 具有良好的场致电子发射特性 [6] 。 目前，SiNWs 的制备主要分为"自上而下"和"自 下而上"两种方式。 "自上而下"主要是利用微纳加 工的方法 [7] ，如反应离子刻蚀、电子束曝光和胶体 晶体刻蚀等； "自下而上"则是利用了化学气相沉积 的方法 [8] ，例如最典型的气-液-固(VLS)生长、固-液-固生长、氧化物辅助生长和激光烧蚀等。上述方 法存在成本昂贵和操作技术复杂等不足。金属辅助 化学刻蚀(Metal Assisted Chemical Etching-MACE) 法具有操作简单、成本低和灵活等特点 [9] 。Cong 等 [10] 用两步 MACE 法制备了垂直均匀的 SiNWs， 在沉积 1 min (15 mmol/L AgNO3，4.6 mol/L HF )和 刻蚀 50 min (0.4 mol/L H2O2，4.8 mol/L HF )的条件 下制备出 SiNWs 的平均长度约为 2 μm。Viridiana 等 [11] 在沉积 30 s (10 mmol/L AgNO3 与 48% HF 体积 比 25 ： 0.5) 和 刻 蚀 30 min ( 体 积 比 HF:H2O2:H2O=2:4:34) 的条件下制备出约 4 μm 长的 SiNWs。虽然 MACE 法有着诸多优点，但传统的 MACE 法制备效率较低。 目前改进 MACE 法主要围 绕提升制备的均匀性、简化制备工艺及大面积制备 技术等方面 [12][13][14]…”