Fluorescent Zn^II Chemosensor Mediated by a 1,8‐Naphthyridine Derivative and It′s Photophysical Properties

Abstract

One of the greatest challenges in using fluorescent chemosensors for highly selective and sensitive transition‐metal ions is finding an efficient and simple method for its synthesis. In this study, a highly efficient fluorescence chemosensor for ZnII was developed from N‐Boc‐L‐proline modified 1,8‐naphthyridine. The fluorescence intensity of the chemosensor was increased significantly only in the presence of ZnII ion which provided a perceived color change for rapid visual sensing, while other metal ions showed fluorescence quenching or little changes. It was worth noting that the chemosensor L distinguished ZnII from CdII commonly having similar properties. The solvent effect and possible bonding mode for fluorescence enhancement have been also discussed. Results of this study indicated that the Boc‐group in l‐proline significantly improved the sensitivity and selectivity for ZnII detection performance, as confirmed by comparison experiments and time dependent‐density functional theory (TD‐DFT) calculations.

Chemical Reactions-based Detection Mechanism for Molecular Communications

“…where C 0 i " C i pu, t " 0q. Adopting C 0 B " 6 ˆ10 21 molecules{m 3 and binding constant K a " κ f {κ b " 6 ˆ10 4 molecules ´1 ¨m3 from [6], based on (25), we choose κ f and κ b as in Table I such that the resulting K a has the same order as the K a in [6].…”

“…Note that, in some MC systems, the signaling molecules should be small and lightweight, e.g., zinc ions or calcium ions, such that they can be easily stored at the transmitter and can diffuse fast from the transmitter to the receiver. On the other hand, the product molecules of the reaction, i.e., the combination of the probe and the analyte [6], which can be detected directly by the receiver, are usually larger molecules and thus may not be directly suitable as signaling molecules. Moreover, when the reaction occurs, a measurable signal, e.g., light, corresponding to the reaction product may be generated but then disappear quickly by a process referred to as quenching [2], [7], [8], which is useful for reducing inter-symbol interference (ISI).…”

Naphthyridine-Based Electron Push–Pull-Type Amine-Reactive Fluorescent Probe for Sensing Amines and Proteins in Aqueous Media

“…Characterization. 1 H, 13 C, 19 F, and 31 P NMR spectra were recorded on Bruker Biospin AVANCE II 600 (600 MHz for 1 H and 151 MHz for 13 C), Bruker Biospin AVANCE III 300 (300 MHz for 1 H and 282 MHz for 19 F), or JEOL JNM-ECZ400S (400 MHz for 1 H, 376 MHz for 19 F, and 162 MHz for 31 P) spectrometers using CDCl 3 , CD 3 CN, or CD 3 OD as the solvent. Chemical shifts (δ) are reported in parts per million (ppm).…”

“…Pale yellow amorphous; 77.3 mg, 97% yield; 1 H NMR (600 MHz, CDCl 3 ): δ 8.12 (br s, 1H), 7.72 (s, 1H), 6.95 (d, J = 9.1 Hz, 1H), 5.98 (br s, 1H), 3.88−3.68 (m, 6H), 2.67 (t, J = 5.8 Hz, 2H), 2.52 (br s, 4H); 13 C NMR (151 MHz, CDCl 3 ): δ 159.5, 157.2, 149.7 (q, 2 J C−F = 35.4 Hz), 136.8 (q, 2 J C−F = 32.6 Hz), 132.5, 122.6 (q, 1 J C−F = 275.8 Hz), 120.8 (q, 1 J C−F = 276.1 Hz), 117.8, 114.6, 110.0, 66.9 (2C), 56. 13 C NMR (151 MHz, CDCl 3 ): δ 160.4, 157.4, 148.5 (q, 2 J C−F = 35.3 Hz), 136.2 (q, 2 J C−F = 32.3 Hz), 134.9 (d, 4 J C−P = 2.9 Hz, 3C), 133.4 (d, 3 J C−P = 9.9 Hz, 6C), 131.1, 130.3 (d, 2 J C−P = 12.4 Hz, 6C), 122.6 (q, 1 J C−F = 275.4 Hz), 120.8 (q, 1 J C−F = 275.7 Hz), 120.0, 117.9 (d, 1 Nap-ER. Pale yellow amorphous; 99.8 mg, quant.…”

Low Molecular Weight Fluorescent Probes (LMFPs) to Detect the Group 12 Metal Triad

“…Another tridentate coordination moiety was incorporated onto a 1,8 naphthyridine scaffold where a protected L-proline was attached to position two on the naphthlyridine ring system, chemosensor 4 [136]. Upon the addition of various metal salts (Li + , K + Cd 2+ , Mn 2+ , Fe 3+ , Cu 2+ , Mg 2+ , Fe 2+ , Ni 2+ , Co 2+ , Hg 2+ , Pb 2+ , Ag + , and Zn 2+ ) in MeOH, only the Zn 2+ ions showed a significant fluorescence enhancement by a factor of 2.5, whereas all other metal ions quenched emission.…”