Department of Chemistry, Nanchang University, Nanchang 330031, China.
Institute for Advanced Study, Nanchang University, Nanchang 330031, China.
Anal Methods. 2023 Oct 19;15(40):5341-5350. doi: 10.1039/d3ay01290e.
Nitrite is a typical food additive and preservative used in the food industry, which has attracted considerable attention due to its severe adverse effects on human health. Herein, a sensitive and highly selective ratiometric colorimetric sensing platform for the detection of nitrite was created based on a polymetallic oxide nanozyme, CoMnO nanofibers (CMO) catalysis integrated with the particular diazotization reaction. The nanozyme has superior oxidase-like activity ( was 0.105 mM and was 63.7 × 10 M S) and could catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to oxidized TMB (oxTMB), as CMO could achieve the conversion of oxygen in the solution to superoxide anion (O˙). In addition, it is interesting to note that oxTMB can be diazotized in the presence of nitrite under acidic conditions, causing a shift in the ratio of nitrite concentration to the absorbance peaks at 450 and 652 nm (/). The ratio of / exhibited a positive linear relationship with the concentration of nitrite within the concentration range of 0.2-200 μM, with a detection limit of 0.094 μM. Simultaneously, this method was also successful in quantifying the nitrite produced by brined and pickled foods and the dynamic tracking of the nitrite levels in various types of dishes. The analysis method not only offers dual-signal ratio sensing with high sensitivity but also holds the benefit of outstanding selectivity for the use of the particular reaction, which has a wide range of application prospects in food safety management.
亚硝酸盐是食品工业中常用的一种典型食品添加剂和防腐剂，由于其对人体健康的严重不良影响而引起了相当大的关注。在此，基于多金属氧化物纳米酶 CoMnO 纳米纤维（CMO）催化与特定的重氮化反应的协同作用，构建了一种用于检测亚硝酸盐的灵敏且高选择性的比率比色传感平台。纳米酶具有优异的过氧化物酶样活性（Km 值为 0.105 mM，Vmax 值为 63.7×10 M S），可以催化 3,3',5,5'-四甲基联苯胺（TMB）的氧化，生成氧化 TMB（oxTMB），因为 CMO 可以将溶液中的氧转化为超氧阴离子（O˙）。此外，有趣的是，在酸性条件下，oxTMB 可以在亚硝酸盐的存在下重氮化，导致亚硝酸盐浓度与 450nm 和 652nm 处吸光度峰比值（/）发生变化。/ 与亚硝酸盐浓度在 0.2-200 μM 浓度范围内呈正线性关系，检测限为 0.094 μM。同时，该方法还成功地定量了腌制和腌制食品中产生的亚硝酸盐，并对各种菜肴中亚硝酸盐水平的动态跟踪。该分析方法不仅提供了高灵敏度的双信号比率传感，而且还具有出色的选择性，这对于利用特定反应具有广泛的应用前景，可应用于食品安全管理。
