Selective and Fast Detection of Fluoride-Contaminated Water Based on a Novel Salen-Co-MOF Chemosensor

Abstract

The development of selective and fast optical sensitive chemosensors for the detection and recognition of different cations and anions in a domain is still a challenge in biological, industrial, and environmental fields. Herein, we report a novel approach for the detection and determination of fluoride ion (F – ) sensing based on a salen-cobalt metal-organic framework (Co(II)-MOF). By a simple method, the Co(II)-MOF was synthesized and characterized using several tools to elucidate the structure and morphology. The photoluminescence (PL) spectrum of the Co(II)-MOF (100.0 nM/L) was examined versus different ionic species like F – , Br – , Cl – , I – , SO 4 2– , and NO 3 – and some cationic species like Mg 2+ , Ca 2+ , Na + , and K + . In the case of F – ions, the PL intensity of the Co(II)-MOF was scientifically enhanced with a remarkable red shift. With the increase of F – concentration, the Co(II)-MOF PL emission spectrum was also professionally enhanced. The limit of detection (LOD) for the Co(II)-MOF chemosensor was 0.24 μg/L, while the limit of quantification (LOQ) was 0.72 μg/L. Moreover, a comparison of the Co(II)-MOF optical approach with other published reports was studied, and the mechanism of interaction was also investigated. Additionally, the applicability of the current Co(II)-MOF approach in different real water samples, such as tap water, drinking water, Nile River water, and wastewater, was extended. This easy-to-use future sensor provides reliable detection of F – in everyday applications for nonexpert users, especially in remote rural areas.

Amino-Functionalized Single-Lanthanide Metal–Organic Framework as a Ratiometric Fluorescent Sensor for Quantitative Visual Detection of Fluoride Ions

“…Conventional techniques for F – detection include ion-selective electrodes, chromatography–mass spectrometry, ion chromatography, and so forth. − However, these methods have shortcomings such as high cost, complex operation, and inconvenient transportation, thereby limiting their application in detecting F – , especially in regions lacking professional supervision. Ratiometric fluorescence sensing method based on the fluorescence intensity ratio of two distinguishable emissive centers is an alternative due to its self-calibration, simple operation, rapid response, high sensitivity, and selectivity. , Several approaches are currently employed in making fluorescent F – probes: nucleophilic addition, cleavage, cyclization reaction, intramolecular hydrogen transfer, as well as the formation of hydrogen bonds with other groups. − By utilizing these strategies, a variety of fluorescent F – probes including fluorescent dyes, polymers, supramolecular gels, and metal–organic frameworks (MOFs) have been proposed. − However, the realization of visual ratiometric and fluorescent detection of F – with fast response and high sensitivity remains a challenge.…”

Fluoridated Water, Effects and Green Removal Techniques

“…This is due to the porous nature and tunability of MOFs with well-positioned ligands that complex with various toxic pollutants. For example, Alhaddad and El-Sheikh, 2021 reported on the use of a salen-cobalt metal organic framework (Co(II)-MOF) to detect fluoride in real water samples [31]. In their study, the photoluminescence spectrum of Co(II)-MOF posted a red shift upon interacting with fluoride ions, even in the presence of other interferents posting limit of detection (LOD) and limit of quantification (LOQ ) of 0.24 μg/L and 0.72 μg/L, respectively.…”

Study on indole adsorption of Zr-and Hf-based metal-organic frameworks for fluoride ion detection

“…Vật liệu xốp như silica xốp (mesoporous silica), vật liệu khung hữu cơ-kim loại (Metal-Organic Framework-MOF) gắn các phân tử tín hiệu có thể được ứng dụng trong cảm biến phát hiện ion fluoride thông qua hiện tượng bật và tắt huỳnh quang. [9][10][11][12] Vật liệu MOF bao gồm hai thành phần chính là cụm kim loại và cầu nối hữu cơ đang thu hút được rất nhiều sự quan tâm nghiên cứu trong khoảng 20 năm gần đây. 13,14 Một số đặc tính nổi bật như lỗ xốp lớn, độ bền nhiệt và độ bền hóa học cao do cấu trúc được thiết kế ban đầu hoặc được biến tính sau khi tổng hợp mà vật liệu MOF có thể được ứng dụng trong nhiều lĩnh vực như hấp phụ và tách lọc khí, xúc tác, cảm biến, vận chuyển thuốc, điện hóa và xử lý môi trường.…”