Light-addressable electrochemical sensing with electrodeposited n-silicon/gold nanoparticle Schottky junctions.
Light-addressable electrochemical sensing with electrodeposited n-silicon/gold nanoparticle Schottky junctions.
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DOI：
10.1021/acs.analchem.0c02512
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发表时间：
2020-07
影响因子：
7.4
通讯作者：
Irina M. Terrero Rodríguez;Alexandra J. Borrill;Katherine Schaffer;Jocelyn B. Hernandez;G. O’Neil
中科院分区：
文献类型：
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作者：
Irina M. Terrero Rodríguez;Alexandra J. Borrill;Katherine Schaffer;Jocelyn B. Hernandez;G. O’Neil
光寻址电化学传感器（LAES）是一类使用光来激活半导体光电极表面上的电化学反应的传感器。在这里，我们研究半导体/金属（肖特基）结之间形成的n型硅和Au纳米粒子作为光寻址电化学传感器。为了证明这一概念，我们制备了n-Si/Au纳米颗粒肖特基结的电沉积和其特征在于，使用扫描电子显微镜，循环伏安法，电化学阻抗谱。我们发现，传感器的表现几乎相同的Au盘电极的氧化的外层氧化还原对（二茂铁甲醇）和两个内层氧化还原对（亚铁氰化钾和多巴胺）。在缓冲多巴胺溶液中，我们观察到广泛的线性范围和亚微摩尔检测限。然后，我们使用局部照明来生成多巴胺的电化学传感器的虚拟阵列，作为规避传感器结垢的策略，这是电化学多巴胺传感器的一个持续存在的问题。通过局部照射光电极的一小部分，通过将光束移动到传感器的新区域，可以在具有单个电连接的单个传感器上进行污垢分析物的许多测量。总之，这些结果为肖特基结光寻址电化学传感器在化学和生物传感中的许多有趣的未来应用铺平了道路。
Light-addressable electrochemical sensors (LAES) are a class of sensors that use light to activate an electrochemical reaction on the surface of a semiconducting photoelectrode. Here, we investigate semiconductor/metal (Schottky) junctions formed between n-type Si and Au nanoparticles as light-addressable electrochemical sensors. To demonstrate this concept, we prepared n-Si/Au nanoparticle Schottky junctions by electrodeposition and characterized them using scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. We found that the sensors behaved almost identically to Au disk electrodes for the oxidation of an outer-sphere redox couple (ferrocene methanol) and two inner-sphere redox couples (potassium ferrocyanide and dopamine). In buffered dopamine solutions, we observed broad linear ranges and sub-micromolar detection limits. We then used local illumination to generate a virtual array of electrochemical sensors for dopamine as a strategy for circumventing sensor fouling, which is a persistent problem for electrochemical dopamine sensors. By locally illuminating a small portion of the photoelectrode, many measurements of fouling analytes can be made on a single sensor with a single electrical connection by moving the light beam to a fresh area of the sensor. Altogether, these results pave the way for Schottky junction light-addressable electrochemical sensors to be useful for a number of interesting future applications in chemical and biological sensing.