The emergence of microfluidic devices integrated with nanostructures enables highly efficient, flexible and controllable biosensing, among which zinc oxide (ZnO) nanostructure-based fluorescence detection has been demonstrated to be a promising methodology due to its high electrical point and unique fluorescence enhancement properties. The optimization of microfluidic synthesis of ZnO nanostructures for biosensing on chip has been in demand due to its low cost and high efficiency, but still the flow-induced growth of ZnO nanostructures is not extensively studied. Here, we report a simple and versatile strategy that could manipulate the local flow field by creating periodically arranged micropillars within a straight microchannel. We have explored the effects of perfusion speed and flow direction of seed solution, localized flow variation of growth solution and growth time on the morphology of nanostructures. This provided a comprehensive understanding which governs nanostructure fabrication controlled by flow. The results demonstrated that localized flow in microfluidic devices was essential for the initiation and growth of zinc oxide crystals, enabling precise control over their properties and morphology. Furthermore, a model protein was used to demonstrate the intrinsic fluorescence enhancement of ZnO nanostructures as an example to reveal the morphology-related enhancement properties.

中文翻译：

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柱阵列微通道中 ZnO 纳米结构的流动诱导制造


与纳米结构集成的微流控器件的出现使得高效、灵活和可控的生物传感成为可能，其中基于氧化锌（ZnO）纳米结构的荧光检测由于其高电点和独特的荧光增强特性而被证明是一种有前途的方法。用于芯片生物传感的ZnO纳米结构的微流体合成优化因其低成本和高效率而受到人们的欢迎，但ZnO纳米结构的流动诱导生长仍然没有得到广泛的研究。在这里，我们报告了一种简单而通用的策略，可以通过在直微通道内创建周期性排列的微柱来操纵局部流场。我们探索了种子溶液的灌注速度和流动方向、生长溶液的局部流动变化和生长时间对纳米结构形态的影响。这提供了对由流动控制的纳米结构制造的全面理解。结果表明，微流体装置中的局部流动对于氧化锌晶体的引发和生长至关重要，从而能够精确控制其性质和形态。此外，以模型蛋白为例，展示了 ZnO 纳米结构的内在荧光增强作用，揭示了与形态相关的增强特性。