Nguyen Phuong Thy, Ahn Hee Tae, Kim Moon Il
Department of BioNano Technology, Gachon University, 1342 Seongnamdae-ro, Sujeong-gu, Seongnam, Gyeonggi 13120, Korea.
Nanomaterials (Basel). 2020 May 8;10(5):895. doi: 10.3390/nano10050895.
A reagent-free colorimetric method for galactose quantification using a composite of cerium oxide nanoparticles (nanoceria) and galactose oxidase (Gal Ox) entrapped in an agarose gel was developed. In the presence of galactose, the Gal Ox entrapped within the agarose gel catalyzed the oxidation of galactose to generate HO, which induced a color change from white to intense yellow. This reaction occurred without any chromogenic substrate. This color transition is presumed to be due to the HO-mediated alteration of the oxidation state of cerium ions present on the surface of the nanoceria. The intensity of color change was quantified by acquiring an image with a conventional smartphone, converting the image to cyan-magenta-yellow-black (CMYK) mode, and subsequently analyzing the image using the ImageJ software. Using this strategy, galactose concentration was specifically determined with excellent sensitivity of as low as 0.05 mM. The analytical utility of the assay was successfully verified by correctly determining diverse levels of galactose in human serum, which is enough to diagnose galactosemia, a genetic disorder characterized by the malfunctioning of enzymes responsible for galactose metabolism. The assay employing a hydrogel composite with entrapped nanoceria and Gal Ox, is a simple, cost-effective, and rapid colorimetric assay for galactose quantification, without using any chromogenic reagent. This cost-effective method has great potential for the diagnosis of galactosemia and is highly promising in comparison to the laborious instrumentation-based methods currently in use.
开发了一种无试剂比色法，用于定量半乳糖，该方法使用包裹在琼脂糖凝胶中的氧化铈纳米颗粒（纳米氧化铈）和半乳糖氧化酶（Gal Ox）的复合物。在半乳糖存在的情况下，包裹在琼脂糖凝胶中的Gal Ox催化半乳糖氧化生成HO，从而导致颜色从白色变为深黄色。该反应无需任何显色底物即可发生。这种颜色转变据推测是由于HO介导了纳米氧化铈表面存在的铈离子氧化态的改变。通过使用传统智能手机获取图像、将图像转换为青-品红-黄-黑（CMYK）模式，随后使用ImageJ软件分析图像来量化颜色变化的强度。使用该策略，能够以低至0.05 mM的出色灵敏度特异性地测定半乳糖浓度。通过正确测定人血清中不同水平的半乳糖，成功验证了该检测方法的分析效用，这些水平足以诊断半乳糖血症，这是一种由负责半乳糖代谢的酶功能失调引起的遗传性疾病。采用包裹有纳米氧化铈和Gal Ox的水凝胶复合物的检测方法，是一种用于半乳糖定量的简单、经济高效且快速的比色检测方法，无需使用任何显色试剂。这种经济高效的方法在半乳糖血症的诊断方面具有巨大潜力，与目前使用的基于繁琐仪器的方法相比，前景十分广阔。
