Leverhulme Research Centre for Forensic Science, School of Science & Engineering, University of Dundee, Dundee, DD1 4GH, UK.
Materials Science & Engineering Research Cluster, School of Science & Engineering, University of Dundee, UK.
Talanta. 2021 Mar 1;224:121875. doi: 10.1016/j.talanta.2020.121875. Epub 2020 Nov 13.
The International Agency for Research cancer (IARC) has classified nitrite in Group 2A of probable carcinogens to human. Herein, we report on the rapid and selective colorimetric detection of nitrite using a chemically modified gold nanoparticle (AuNP)-cerium oxide (CeO) NP-anchored graphene oxide (GO) hybrid nanozyme in a catalytic colorimetric assay where nitrite acts as the main oxidant/target analyte and 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate. CeO NPs and GO were synthesized separately and incorporated in-situ, in a synthetic solution involving the chemical reduction of Au salt to AuNPs. The chemical modification process aided the adsorption of CeO NPs and AuNPs on GO nanosheets, yielding a highly catalytic AuNP-CeO NP@GO nanohybrid material. Under optimum experimental conditions, a novel colorimetric assay for nitrite recognition was constructed in which AuNP-CeO NP@GO hybrid nanozyme catalysed the oxidation of TMB in the presence of nitrite prepared in a 2-(n-morpholino)ethanesulfonic acid-2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)propane-1,3-diol-tris(hydroxymethyl)aminomethane acetate (MES-BIS-TRIS-Trisma Ac)-citric acid buffer solution, pH 2. Nitrite was quantitatively detected in a concentration dependent manner from 100 μM to 5000 μM with a correlation coefficient of 0.9961 and a limit of detection of 4.6 μM. Selective detection of nitrite was confirmed by the generation of a unique green colour reaction upon nitrite interaction in the AuNP-CeO NP@GO hybrid nanozyme redox cycle with TMB. None of the several tested metal ions and including HO yielded a positive colour response, thus demonstrating the superior selectivity of the catalytic colorimetric assay for nitrite recognition. The AuNP-CeO NP@GO hybrid nanozyme catalytic colorimetric assay was successfully applied in the detection of nitrite in tap water.
国际癌症研究机构（IARC）已将亚硝酸盐归类为对人类可能致癌的 2A 组。在此，我们报告了一种使用化学修饰的金纳米粒子（AuNP）-氧化铈（CeO）纳米粒子锚定的氧化石墨烯（GO）杂化纳米酶在催化比色测定中亚硝酸盐的快速和选择性比色检测，其中亚硝酸盐作为主要氧化剂/目标分析物，3,3',5,5'-四甲基联苯胺（TMB）作为底物。CeO NPs 和 GO 分别合成并原位掺入包括 Au 盐化学还原为 AuNPs 的合成溶液中。化学修饰过程有助于 CeO NPs 和 AuNPs 在 GO 纳米片上的吸附，得到高度催化的 AuNP-CeO NP@GO 纳米杂化材料。在最佳实验条件下，构建了一种新的亚硝酸盐识别比色测定法，其中 AuNP-CeO NP@GO 杂化纳米酶在含有亚硝酸盐的情况下催化 TMB 的氧化，亚硝酸盐在 2-（n-吗啉基）乙磺酸-2-[双（2-羟乙基）氨基]-2-（羟甲基）丙烷-1,3-二醇-tris（羟甲基）氨基甲烷乙酸盐（MES-BIS-TRIS-Trisma Ac）-柠檬酸缓冲溶液中制备，pH 值为 2。亚硝酸盐在 100 μM 至 5000 μM 的浓度范围内呈定量依赖性检测，相关系数为 0.9961，检测限为 4.6 μM。通过在 AuNP-CeO NP@GO 杂化纳米酶氧化还原循环中与 TMB 相互作用产生独特的绿色颜色反应，确认了对亚硝酸盐的选择性检测。在 AuNP-CeO NP@GO 杂化纳米酶催化比色测定中亚硝酸盐的选择性检测中，没有一种测试的金属离子包括 HO 产生阳性颜色反应，因此证明了该催化比色测定法对亚硝酸盐识别的优异选择性。AuNP-CeO NP@GO 杂化纳米酶催化比色测定法成功应用于自来水中亚硝酸盐的检测。
