College of Chemistry and Food Engineering, Changsha University of Science & Technology, Changsha, 410114, China.
College of Automotive and Mechanical Engineering, Changsha University of Science & Technology, Changsha, 410114, China.
Mikrochim Acta. 2021 Feb 18;188(3):90. doi: 10.1007/s00604-021-04718-z.
The design and construction of a novel magnetic resonance sensor (MRS) is presented for bisphenol A (BPA) detection. The MRS has been built based on the core component of magnetic FeO nanoparticles (~ 40 nm), which were uniformly distributed in nanoporous carbon (abbreviated as FeO@NPC). The synthesis was derived from the calcination of the metal organic framework (MOF) precursor of Fe-MIL-101 at high temperature. FeO@NPC was confirmed with enhanced transversal relaxation with r value of 118.2 mM s, which was around 1.7 times higher than that of the naked FeO nanoparticle. This enhancement is attributed to the excellent proton transverse relaxation rate of FeO@NPC caused by the reduced self-diffusion coefficient of water molecules in the vicinity of FeO nanoparticles in the nanoporous carbon. BPA antibody (Ab) and antigen (Ag)-ovalbumin (OVA) were immobilized onto the FeO@NPC to form Ab-FeO@NPC and Ag-FeO@NPC, respectively. These two composites can cause the three-dimensional assembly of FeO@NPC via immunological recognition. The presence of BPA can compete with antigen-OVA to combine with Ab-FeO@NPC, thereby breaking the assembly process (disassembly). The difference in the change of the T value before and after adding BPA can thus be used to monitor BPA. The proposed MRS not only revealed a wide linear range of BPA concentration from 0.05 to 50 ng mL with an extremely low detection limit of 0.012 ng mL (S/N = 3), but also displayed high selectivity towards matrix interferences. The recoveries of BPA ranged from 95.6 to 108.4% for spiked tea π, and 93.4 to 104.7% for spiked canned oranges samples, respectively, and the RSD (n = 3) was less than 4.4% for 3 successive assays. The versatility of FeO@NPC with customized relaxation responses provides the possibility for the adaptation of magnetic resonance platforms for food safety development. The magnetic Fe3O4 nanoparticles are uniformly dispersed in the nanoporous carbon (Fe3O4@NPC), which derived from the calcinating of the metal organic framework (MOF) precursor of Fe-MIL-101. And the magnetic FeO@NPCs are adopted for the construction of magnetic resonance sensor (MRS) for bisphenol A (BPA) detection.
本文提出了一种用于双酚 A（BPA）检测的新型磁共振传感器（MRS）的设计与构建。该 MRS 的核心组件是磁性 FeO 纳米粒子（40nm），均匀分布在纳米多孔碳（简称 FeO@NPC）中。该合成方法源自高温下金属有机骨架（MOF）前体的煅烧。FeO@NPC 的横向弛豫增强，r 值为 118.2mM·s，约为裸露 FeO 纳米粒子的 1.7 倍。这种增强归因于 FeO@NPC 中水分子自扩散系数的降低，导致 FeO 纳米粒子附近质子的横向弛豫率显著提高。BPA 抗体（Ab）和抗原（Ag）-卵清蛋白（OVA）分别固定在 FeO@NPC 上，形成 Ab-FeO@NPC 和 Ag-FeO@NPC。这两种复合材料可以通过免疫识别使 FeO@NPC 发生三维组装。BPA 的存在可以与抗原-OVA 竞争与 Ab-FeO@NPC 结合，从而破坏组装过程（解组装）。因此，加入 BPA 前后 T 值变化的差异可用于监测 BPA。所提出的 MRS 不仅显示出从 0.05 到 50ngmL 的宽 BPA 浓度线性范围，检测限极低（0.012ngmL，S/N=3），而且对基质干扰具有高选择性。BPA 在茶叶 π 中的加标回收率为 95.6%108.4%，在罐装橙子样品中的回收率为 93.4%~104.7%，连续 3 次测定的 RSD（n=3）小于 4.4%。FeO@NPC 具有定制弛豫响应的多功能性为食品安全开发的磁共振平台的适应提供了可能性。磁性 Fe3O4 纳米粒子均匀分散在纳米多孔碳（Fe3O4@NPC）中，这是由 Fe-MIL-101 的金属有机骨架（MOF）前体煅烧而来。磁性 FeO@NPC 被用于构建用于双酚 A（BPA）检测的磁共振传感器（MRS）。
