Kim Andrew, Varga Imre, Adhikari Arindam, Patel Rajkumar
Department of Chemical Engineering, The Cooper Union for the Advancement of Science and Art, New York, NY 10003, USA.
Institute of Chemistry, Eötvös Loránd University, 1117 Budapest, Hungary.
Nanomaterials (Basel). 2021 Oct 22;11(11):2809. doi: 10.3390/nano11112809.
Layered double hydroxides (LDHs) have attracted considerable attention as promising materials for electrochemical and optical sensors owing to their excellent catalytic properties, facile synthesis strategies, highly tunable morphology, and versatile hosting ability. LDH-based electrochemical sensors are affordable alternatives to traditional precious-metal-based sensors, as LDHs can be synthesized from abundant inorganic precursors. LDH-modified probes can directly catalyze or host catalytic compounds that facilitate analyte redox reactions, detected as changes in the probe's current, voltage, or resistance. The porous and lamellar structure of LDHs allows rapid analyte diffusion and abundant active sites for enhanced sensor sensitivity. LDHs can be composed of conductive materials such as reduced graphene oxide (rGO) or metal nanoparticles for improved catalytic activity and analyte selectivity. As optical sensors, LDHs provide a spacious, stable structure for synergistic guest-host interactions. LDHs can immobilize fluorophores, chemiluminescence reactants, and other spectroscopically active materials to reduce the aggregation and dissolution of the embedded sensor molecules, yielding enhanced optical responses and increased probe reusability. This review discusses standard LDH synthesis methods and overviews the different electrochemical and optical analysis techniques. Furthermore, the designs and modifications of exemplary LDHs and LDH composite materials are analyzed, focusing on the analytical performance of LDH-based sensors for key biomarkers and pollutants, including glucose, dopamine (DA), HO, metal ions, nitrogen-based toxins, and other organic compounds.
层状双氢氧化物（LDHs）因其优异的催化性能、简便的合成策略、高度可调的形态和多样的容纳能力，作为电化学和光学传感器的有前景材料而备受关注。基于LDH的电化学传感器是传统贵金属基传感器的经济实惠替代品，因为LDHs可由丰富的无机前体合成。LDH修饰的探针可直接催化或容纳促进分析物氧化还原反应的催化化合物，通过探针电流、电压或电阻的变化进行检测。LDHs的多孔和层状结构允许分析物快速扩散，并提供丰富的活性位点以提高传感器灵敏度。LDHs可由诸如还原氧化石墨烯（rGO）或金属纳米颗粒等导电材料组成，以提高催化活性和分析物选择性。作为光学传感器，LDHs为协同的客体-主体相互作用提供了宽敞、稳定的结构。LDHs可固定荧光团、化学发光反应物和其他光谱活性材料，以减少嵌入的传感器分子的聚集和溶解，产生增强的光学响应并提高探针的可重复使用性。本文综述了标准的LDH合成方法，并概述了不同的电化学和光学分析技术。此外，分析了示例性LDHs和LDH复合材料的设计和修饰，重点关注基于LDH的传感器对关键生物标志物和污染物（包括葡萄糖、多巴胺（DA）、过氧化氢、金属离子、氮基毒素和其他有机化合物）的分析性能。
