Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
Anal Chem. 2022 Jan 18;94(2):1126-1134. doi: 10.1021/acs.analchem.1c04207. Epub 2021 Dec 22.
Semicarbazide (SEM) is a widespread carcinogenic and neurotoxic food contaminant, originating from the metabolite of antibiotic nitrofurazone, which is used in aquaculture, or thermal decomposition byproduct of a flour blowing agent azodicarbonamide. Although optical detection technologies are powerful tools considering the advantages of fast response and visualization detection, there are few optical nanosensors for highly sensitive and visual assays of SEM due to no luminescence response and UV absorbance of SEM. Herein, an upconversion luminescence (UCL)-based nanosensor was designed for visual detection of SEM with high sensitivity and good selectivity. The nanosensor was constructed by combining upconversion nanoparticles (UCNPs) and phosphomolybdic acid (PMA), which was used as the specific recognition element of SEM. The developed nanosensor exhibited selective absorbance enhancement and UCL quenching behavior with the addition of SEM based on the inner filter effect (IFE). Since the change in absorbance translated into an exponential change in the luminescence, the sensitivity of the nanosensor was greatly improved. The nanosensor realized a highly sensitive and visual response to SEM in the linear range of 0.5-16 μM with a low limit of detection of 58 nM. Moreover, satisfactory recovery values ranging from 90 to 112% in spiked real samples indicated the practical applicability of the nanosensor. The nanosensor designed here provides a sensitive and convenient sensing strategy for visual detection of hazardous substances and is expected to develop the upconversion sensing application in food safety.
氨基脲（SEM）是一种广泛存在的致癌和神经毒性食品污染物，来源于抗生素呋喃西林的代谢物，该物质用于水产养殖，或面粉发泡剂偶氮二甲酰胺的热分解副产物。尽管光学检测技术具有快速响应和可视化检测的优势，但由于 SEM 没有发光响应和紫外吸收，因此很少有光学纳米传感器用于 SEM 的高灵敏度和可视化分析。在此，设计了一种基于上转换发光（UCL）的纳米传感器，用于 SEM 的高灵敏度和良好选择性的可视化检测。该纳米传感器通过将上转换纳米粒子（UCNP）和磷钼酸（PMA）结合而成，后者被用作 SEM 的特定识别元件。基于内滤效应（IFE），纳米传感器在添加 SEM 后表现出选择性的吸光度增强和 UCL 猝灭行为。由于吸光度的变化转化为发光的指数变化，因此纳米传感器的灵敏度大大提高。纳米传感器在 0.5-16 μM 的线性范围内对 SEM 实现了高灵敏度和可视化响应，检测限低至 58 nM。此外，在加标实际样品中回收率值在 90%至 112%之间，表明纳米传感器具有令人满意的实际适用性。这里设计的纳米传感器为危险物质的可视化检测提供了一种灵敏便捷的传感策略，有望推动上转换传感技术在食品安全领域的应用。
