Absorption competition quenching mechanism of porous covalent organic polymer as luminescent sensor for selective sensing Fe³⁺

Abstract

Developing luminescent sensors for highly selective detecting Fe3+ is a very important topic, because Fe3+ plays a key role in human's living environment. In this work, we use tetrakis (p‐broMophenyl) methane as a monomer, and 4,4′‐Dibromobiphenyl, 9,10‐Dibromoanthracene, and 1,4‐dibromonaphthalene as another monomer to synthesize three porous luminescent covalent‐organic polymers (COPs) by Ni‐catalyzed Yamamoto reaction respectively. Results indicate that these COPs exhibit excellent selectivity and sensitivity for detecting Fe3+ in 10 wt% ethanol aqueous solutions. By using the three COPs as representative sensors, we reveal the absorption competition quenching (ACQ) mechanism of the COPs for sensing Fe3+, i. e., the absorption spectrum overlap between the COPs and analytes leads to a competition of absorption of the light source between the analyte and the COP material, which causes the luminescence quenching of the COPs in detecting analytes. For all cases studied here, the ACQ mechanism takes effect. It is expected that the ACQ mechanism provided here can be used as an efficient strategy to design the new luminescent sensors for applications of interest.

Facile Preparation of Micro/Mesoporous Conjugated Polymers for Multifunctional Sensing and Separation Applications

“…N/S atoms from the pyridyl nitrogen, amide group could act as binding sites to interact with metal ions efficiently . MCP‐5, MCP‐6 and MCP‐7 can also recognize Fe 3+ ions, the mechanism could be due to the absorption competition quenching ,…”

Morphological Diversity in Nanoporous Covalent Organic Materials Derived from Viologen and Pyrene

“…Both polymeric materials are nanoporous, cationic, and highly stable in water, even in the presence of acid (1 M HCl) or base (1 M NaOH). Their porosity and ionic surfaces are responsible for high affinities and adsorption capacities for iodine vapor.Porous covalent organic polymers (COPs) are well known for their diverse applications in fields such as gas storage and separation, [1][2][3][4] catalysis, [5][6][7][8] sensing, [9,10] drug delivery, [11] and environmental remediation. [12] In order to design COPs with improved functionality, considerable research has been undertaken to understand the relationship between the morphologies and properties of these materials.…”

New Polyhedral Oligomeric Silsesquioxanes-Based Fluorescent Ionic Liquids: Synthesis, Self-Assembly and Application in Sensors for Detecting Nitroaromatic Explosives

“…Thus, the absorption by the explosives filters the light absorbed by the IL-POSSs, resulting in fluorescence quenching. With regards to the fluorescence emission mechanism, after the fluorescent materials absorbed the light or energy, the electrons would be transitioned from the ground state (S 0 ) to the excited states (S 1 , S 2 ) [41], and due to the unstable state, they would release energy to achieve an absorption competition of the light source energy between the materials and the analytes after a series of vibrations. Consequently, the coexistence of the electron transfer effect and competitive absorption leads to fluorescence quenching behaviors.…”