Rotating the C–N Bond in a Coumarin–Pyridine-Based Sensor for Pattern Recognition of Versatile Metal Ions

Abstract

A cross-reactive sensor array is powerful for high-throughput discrimination of various kinds of metal ions. However, the construction of a multicomponent sensor array is always time-consuming and cost-ineffective. Herein, a practical four-component X1-based sensor array (X1SA) was obtained by simply dissolving a single dye molecule X1 in respective solvents such as methanol, ethanol, dimethyl sulfoxide, and acetonitrile. In this design, X1 exhibits strong solvatochromic fluorescence properties via an excited-state intramolecular proton transfer and intramolecular charge transfer combined mechanism. Moreover, rotation of the C− N bond between the pyridine and coumarin units in X1 enabled it to coordinate with metal ions through different binding modes, which acted as an additional dimension of the sensor array. Inspired by this C−N bond rotation strategy, X1SA was determined to be powerful in discriminating 20 kinds of metal ions in both phosphate-buffered saline and 5% serum media in a range of 0.1−100 μM. In addition, the sensor array was also successfully applied in differentiating similar and mixed metal ions such as Fe 3+ /Fe 2+ , Cd 2+ /Hg 2+ , and Sn 2+ /Pb 2+ in serum samples, which is meaningful for investigating the biological roles of iron and early diagnosis of related metal poisoning accidents.

Synthesis and Characterization of Newly Designed and Highly Solvatochromic Double Squaraine Dye for Sensitive and Selective Recognition towards Cu2+

“…Considering the two dipolar organic solvents acetonitrile (ACN) and DMF with high and nearly similar dielectric constants [ 40 ] of 37.5 and 37.8 exhibit contrasting color and absorption spectral features with λ max of 592 nm and 728 nm, respectively. We investigated the spectral changes of the DSQ dye in the different ratio of binary solvent mixtures consisted of ACN and DMF and results are shown in Figure 2 c. The excited-state interactions such as change in the conformation, charge (electron/proton) transfer, and non-covalent interactions with solvent molecules such as van der Waals forces have been widely used to explain differential solvatochromic behavior in the functional organic molecules [ 41 , 42 , 43 , 44 , 45 , 46 ]. This contrasting solvatochromic behavior in these solvents can be explained considering the differential aggregation behavior of the DSQ dye taking dipole-dipole, and hydrogen bonding interactions between the dye and solvent molecules.…”

Benzilbis(2-hydroxyanil) – highly efficient ligand for ferric ion (Fe3+) sensing

“…The origin of the selective increase in the fluorescence intensity may be due to the chelation enhanced fluorescence effect in the presence of Fe 3+ cations. 26 Another important aspect derived from the sensing studies is that L is selective in sensing Fe 3+ , whereas Fe 2+ ions are not detected, portraying the exclusive specificity of the ligand towards Fe 3+ ions.…”

荧光碳点基多通道传感器阵列快速鉴别金属离子

“…因此, 准 确检测复杂体系中的金属离子对改善公众健康和控 制环境污染至关重要 [8,9] . 近年来原子吸收光谱法(AAS)、电感耦合等离子 体-质谱(ICP-MS)、原子发射光谱法(AFS)等被广泛用 于多种金属离子的检测 [10][11][12] . 然而, 这些方法存在检 测成本高、设备昂贵、需专业操作人员等问题, 使其 应用受限.…”