Nouri Maryam, Hajiaghababaei Leila, Badiei Alireza, Khalilian Faezeh, Mazloomifar Ali
Department of Chemistry, Yadegar-e-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, Tehran, Iran.
School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
Sci Rep. 2024 Jul 16;14(1):16376. doi: 10.1038/s41598-024-66453-8.
One of the important problems in the environment is heavy metal pollution, and fluorescence is one of the best methods for their detection due to its sensitivity, selectivity, and relatively rapid and easy operation. In this study, 1,8-diaminonaphthalene functionalized super-stable mesoporous silica (DAN-LUS-1) was synthesized and used as a fluorescence probe to identify Hg and Fe in food samples. The TGA and FT-IR spectra illustrated that 1,8-diaminonaphthalene was grafted into LUS-1. XRD patterns verified that the LUS-1 and functionalized mesoporous silica have a hexagonal symmetrical array of nano-channels. SEM images showed that the rod-like morphology of LUS-1 was preserved in DAN-LUS-1. Also, surface area and pore diameter decreased from 824 m g⁻ and 3.61 nm for the pure LUS-1 to 748 m g⁻ and 3.43 nm for the DAN-LUS-1, as determined by N₂ adsorption-desorption isotherms. This reduction demonstrated that 1,8-diaminonaphthalene immobilized into the pore of LUS-1. The DAN-LUS-1 fluorescence properties as a chemical sensor were studied with a 340/407 nm excitation/emission wavelength that was quenched by Hg and Fe ions. Hg and Fe were quantified using the fluorescence response in the working range 8.25-13.79 × 10 and 3.84-10.71 × 10 mol/L, with detection limits of 8.5 × 10 M and 1.3 × 10 M, respectively. Hg and Fe were measured in vetiver grass and spinach. Since the Fe quenching can move in the opposite direction with sodium hexametaphosphate (SHMP) as a hiding compound for Fe, consequently, the circuit logic system was established with Fe, Hg, and SHMP as inputs and the fluorescent quench as the output.
环境中的重要问题之一是重金属污染，而荧光因其灵敏度、选择性以及相对快速简便的操作，成为检测重金属的最佳方法之一。在本研究中，合成了1,8 - 二氨基萘功能化的超稳定介孔二氧化硅（DAN - LUS - 1），并将其用作荧光探针来识别食品样品中的汞和铁。热重分析（TGA）和傅里叶变换红外光谱（FT - IR）表明1,8 - 二氨基萘接枝到了LUS - 1上。X射线衍射（XRD）图谱证实LUS - 1和功能化介孔二氧化硅具有纳米通道的六方对称阵列。扫描电子显微镜（SEM）图像显示LUS - 1的棒状形态在DAN - LUS - 1中得以保留。此外，通过N₂吸附 - 解吸等温线测定，比表面积和孔径从纯LUS - 1的824 m²/g和3.61 nm降至DAN - LUS - 1的748 m²/g和3.43 nm。这种降低表明1,8 - 二氨基萘固定在了LUS - 1的孔中。以340/407 nm的激发/发射波长研究了DAN - LUS - 1作为化学传感器的荧光特性，该荧光被汞和铁离子淬灭。在8.25 - 13.79×10⁻⁶和3.84 - 10.71×10⁻⁶mol/L的工作范围内，利用荧光响应定量汞和铁，检测限分别为8.5×10⁻⁷M和1.3×10⁻⁶M。在香根草和菠菜中测定了汞和铁。由于铁的淬灭可以通过六偏磷酸钠（SHMP）作为铁的掩蔽化合物而向相反方向移动，因此，建立了以铁、汞和SHMP为输入，荧光淬灭为输出的电路逻辑系统。
