Polyphenylene sulfide paper-based sensor modified by Eu-MOF for efficient detection of Fe3+

Fabrication of the Antibiotic Sensor by the Multifunctional Stable Adjustable Luminescent Lanthanide Metal-Organic Frameworks

In recent years, the irrational use of antibiotics has become very widespread. It is necessary to regulate this phenomenon through antibiotic detection. In this work, a series of isomorphic Ln-MOFs (Ln = Tb³⁺ and Eu³⁺) were synthesized from 1,3,5-tri(4-carboxyphenyl)benzene (H₃L) and Ln³⁺ by the solvothermal method for the first time. A series of 1-Eu_xTb_1-x with different luminescence were doped by changing the molar ratio of Tb³⁺ and Eu³⁺. Ln³⁺ forms a 4-connected 2D network structure through self-assembly with fully deprotonated L^3-. It shows good chemical stability in water, and its luminescence is not affected by aqueous solutions with different pH values. 1-Eu demonstrates rapid and sensitive detection capabilities for MDZ and TET with good recyclability and low detection limits (10^-5). In order to increase the practicability of 1-Eu, two portable sensors have been prepared, in which the fluorescent film (Film@1-Eu) has a detection limit of 10^-4, and the sensitivity is only less than 10% of the titration results. A portable fluorescent test paper can reach the detection limit of 14.7 ppm. This study provides a new idea for the application of stable multifunctional materials in the field of fluorescence sensing.

Recent advances in determination applications of emerging films based on nanomaterials

Sensitive and facile detection of analytes is crucial in various fields such as agriculture production, food safety, clinical diagnosis and therapy, and environmental monitoring. However, the synergy of complicated sample pretreatment and detection is an urgent challenge. By integrating the inherent porosity, processability and flexibility of films and the diversified merits of nanomaterials, nanomaterial-based films have evolved as preferred candidates to meet the above challenge. Recent years have witnessed the flourishment of films-based detection technologies due to their unique porous structures and integrated physical/chemical merits, which favors the separation/collection and detection of analytes in a rapid, efficient and facile way. In particular, films based on nanomaterials consisting of 0D metal-organic framework particles, 1D nanofibers and carbon nanotubes, and 2D graphene and analogs have drawn increasing attention due to incorporating new properties from nanomaterials. This paper summarizes the progress of the fabrication of emerging films based on nanomaterials and their detection applications in recent five years, focusing on typical electrochemical and optical methods. Some new interesting applications, such as point-of-care testing, wearable devices and detection chips, are proposed and emphasized. This review will provide insights into the integration and processability of films based on nanomaterials, thus stimulate further contributions towards films based on nanomaterials for high-performance analytical-chemistry-related applications.

Insights into the luminescent properties of poly(phenylene sulfide)–grafted metal–organic framework (Tb–MOF–PPS) via copolymerization

In this study, a novel poly(phenylene sulfide)-grafted metal-organic framework (Tb–MOF–PPS) was fabricated. Initially, 2,5-dichloroterephthalic acid and TbCl3·6H2O were used as raw materials to synthesize the dihalogenated MOF (Tb–MOF) through ultrasound irradiation and hydrothermal methods. Subsequently, Tb–MOF was added at different mole proportions (2.5, 5, 7.5, and 10%) for the copolymerization of PPS, and a serial of Tb–MOF–PPS composites were successfully obtained. Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy proved that the Tb–MOF was covalently connected to PPS. The introduction of the Tb–MOF had no evident influence on the thermal properties of the composites. Additionally, the fluorescence characteristics revealed that the fluorescence excitation and emission spectra of the composites had a large redshift compared with that of PPS and possessed visible-light photoluminescence properties. These results indicate that the composites obtained can be used as optical sensors.

Hospitals and Laboratories on Paper-Based Sensors: A Mini Review

With characters of low cost, portability, easy disposal, and high accuracy, as well as bulky reduced laboratory equipment, paper-based sensors are getting increasing attention for reliable indoor/outdoor onsite detection with nonexpert operation. They have become powerful analysis tools in trace detection with ultra-low detection limits and extremely high accuracy, resulting in their great popularity in medical detection, environmental inspection, and other applications. Herein, we summarize and generalize the recently reported paper-based sensors based on their application for mechanics, biomolecules, food safety, and environmental inspection. Based on the biological, physical, and chemical analytes-sensitive electrical or optical signals, extensive detections of a large number of factors such as humidity, pressure, nucleic acid, protein, sugar, biomarkers, metal ions, and organic/inorganic chemical substances have been reported via paper-based sensors. Challenges faced by the current paper-based sensors from the fundamental problems and practical applications are subsequently analyzed; thus, the future directions of paper-based sensors are specified for their rapid handheld testing.