Department of Chemistry, University of Central Florida, Orlando, Florida 32816, United States.
Department of Chemistry and CREOL/The School of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, United States.
ACS Appl Mater Interfaces. 2020 Nov 4;12(44):49502-49509. doi: 10.1021/acsami.0c16369. Epub 2020 Oct 22.
Blood glucose monitoring is an essential but painful component of diabetes management, so it is urgent to develop simple, convenient, and noninvasive glucose monitoring methods as alternatives. Because the glucose level in urine is directly related to the blood glucose, urine can be an alternative for blood glucose monitoring. Herein, we report the development of a new and highly sensitive noninvasive colorimetric assay to detect the glucose content in urine samples using gold bipyramids (GBPs). The principle of this method is to utilize hydrogen peroxide (HO), the oxidation product of glucose, to etch GBPs, where the urine glucose will be quantified based on the displacement of the absorption peak of GBPs. The unique morphology (sharp tips) and etching mechanism (from tips) of GBPs determine the high sensitivity of this assay. Under optimal conditions, this colorimetric assay shows a dynamic range of 0.5-250 μM and a detection limit of 0.34 μM for artificial urine samples. This detection capability is ideal when sample dilution is necessary. Another advantage is that the color change of the GBP solution in this assay is convenient for the visual readout of the urine glucose semiquantitatively by the naked eye. Furthermore, it has been demonstrated here that the iodide ion has the horseradish peroxidase (HRP) activity and can be used alone to promote the reduction reaction of HO, which eliminates the use of HRP enzymes, simplifies the reaction, and reduces costs. The role of iodide ions has been studied and mainly attributed as a catalyst with I as the reaction intermediate, which reduced the activation energy for the reduction of HO.
血糖监测是糖尿病管理中必不可少但又很痛苦的一个环节，因此开发简单、方便、无创的血糖监测方法迫在眉睫。由于尿液中的葡萄糖水平与血糖直接相关，因此尿液可以作为血糖监测的替代物。在此，我们报告了一种新的、高灵敏度的非侵入性比色分析方法的发展，该方法使用金双锥（GBPs）来检测尿液样本中的葡萄糖含量。该方法的原理是利用葡萄糖的氧化产物过氧化氢（HO）来蚀刻 GBPs，根据 GBPs 的吸收峰位移来定量尿液中的葡萄糖。GBPs 的独特形态（尖锐的尖端）和蚀刻机制（从尖端开始）决定了该分析方法的高灵敏度。在最佳条件下，该比色分析对人工尿液样本的检测范围为 0.5-250 μM，检测限为 0.34 μM。当需要对样品进行稀释时，这种检测能力非常理想。另一个优点是，该分析中 GBP 溶液的颜色变化可以通过肉眼方便地对尿液葡萄糖进行半定量读取。此外，这里还证明了碘离子具有辣根过氧化物酶（HRP）的活性，可以单独用作促进 HO 还原反应的催化剂，从而消除了 HRP 酶的使用，简化了反应并降低了成本。已经研究了碘离子的作用，主要归因于作为催化剂的碘离子作为反应中间体，降低了 HO 还原反应的活化能。
