Department of Microelectronics, Nankai University, Tianjin 300071, China.
Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, School for Radiological & Interdisciplinary Sciences (RAD-X), Soochow University, Suzhou 215123, China.
Biosens Bioelectron. 2015 May 15;67:296-302. doi: 10.1016/j.bios.2014.08.037. Epub 2014 Aug 23.
In this work, low-toxicity fluorescent gold nanoclusters (AuNCs) based photoelectrochemical sensors were developed for H2O2 and glucose detection. Herein, the processes used to fabricate the sensors and the photoelectrochemical performances of the sensors under different conditions were presented. Based on the energy band levels of the AuNCs and electron tunneling processes, a detailed photoelectrochemical sensing model was given. The designed sensors were then used for H2O2 and glucose detection without any extra modification of the AuNCs or complex enzyme immobilization. The results demonstrate that the AuNCs allow for H2O2 sensing based on their capacity for both fluorescence and catalysis. Indeed, it was observed that H2O2 was catalyzed by the AuNCs and reduced by photoinduced electrons derived from excited AuNCs. Furthermore, an enhancement in photocurrent amplitude followed the increase in the concentrations of H2O2 and glucose. The effects of the types of ligands surrounding the AuNCs and the applied potential on the output photocurrent were well studied to optimize the measurement conditions. The sensitivity and LOD of MUA-AuNCs at -500 mV were 4.33 nA/mM and 35 μM, respectively. All experimental results indicated that AuNCs could not only serve as a promising photoelectrical material for building the photoelectrochemical biosensors but as catalysts for H2O2 sensing.
在这项工作中，开发了基于低毒性荧光金纳米团簇（AuNCs）的光电化学传感器，用于检测 H2O2 和葡萄糖。本文介绍了传感器的制备过程以及在不同条件下传感器的光电化学性能。基于 AuNCs 的能带水平和电子隧道过程，给出了详细的光电化学传感模型。然后，无需对 AuNCs 进行任何额外修饰或复杂的酶固定化，即可将设计的传感器用于 H2O2 和葡萄糖检测。结果表明，AuNCs 可以基于其荧光和催化能力来检测 H2O2。实际上，观察到 AuNCs 可以催化 H2O2，并被激发的 AuNCs 产生的光致电子还原。此外，随着 H2O2 和葡萄糖浓度的增加，光电流幅度增强。还研究了 AuNCs 周围配体的类型和施加电位对输出光电流的影响，以优化测量条件。在-500 mV 时，MUA-AuNCs 的灵敏度和 LOD 分别为 4.33 nA/mM 和 35 μM。所有实验结果表明，AuNCs 不仅可以作为构建光电化学生物传感器的有前途的光电材料，还可以作为 H2O2 检测的催化剂。
