Bimetallic organic frame nanosheet fluorescent probe used for detecting tetracycline and folic acid

Recent Advances of Bimetallic-Metal Organic Frameworks: Preparation, Properties, and Fluorescence-Based Biochemical Sensing Applications

Bimetallic-metal organic frameworks (BiM-MOFs) or bimetallic organic frameworks represent an innovative and promising class of porous materials, distinguished from traditional monometallic MOFs by their incorporation of two metal ions alongside organic linkers. BiM-MOFs, with their unique crystal structure, physicochemical properties, and composition, demonstrate distinct advantages in the realm of biochemical sensing applications, displaying improvements in optical properties, stability, selectivity, and sensitivity. This comprehensive review explores into recent advancements in leveraging BiM-MOFs for fluorescence-based biochemical sensing, providing insights into their design, synthesis, and practical applications in both chemical and biological sensing. Emphasizing fluorescence emission as a transduction mechanism, the review aims to guide researchers in maximizing the potential of BiM-MOFs across a broader spectrum of investigations. Furthermore, it explores prospective research directions and addresses challenges, offering valuable perspectives on the evolving landscape of fluorescence-based probes rooted in BiM-MOFs.

Highly photoluminescent tryptophan-coated copper nanoclusters based turn-off fluorescent probe for determination of tetracyclines

Employing cheap Cu nanoclusters to design a novel fluorescent probe have promising opportunities in the field of optical sensors. Here, we fabricated a highly photoluminescent D-tryptophan (D-Trp)-coated Cu nanoclusters (Trp-Cu NCs) by rapid microwave-assisted method to achieve precise quantification of tetracyclines (TC). Due to protecting groups of Trp, the synthesized Trp-Cu NCs have remarkable fluorescence stability with a quantum yield reached 12.5%. A distinct fluorescence quenching with the incremental addition of TC via the internal filtration effect (IFE). Based on turn-off fluorescence within 1 min, a detection method for detecting TC was constructed with a linear range of 0.3-120 μM and a limit of detection (LOD) of 0.12 μM. Besides, the proposed fluorescent probe has been employed for the determination of practical samples such as water samples, milk and honey, and exhibited satisfactory recoveries of 96.1%-108.2%, with relative standard deviations (RSD) lower than 5.0%. This is a sensitive, rapid and easily recognizable Trp-Cu NCs based sensing platform for the determination of TC, which could offer a powerful tool for ensuring food safety.

Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

Increasing trace levels of antibiotics and hormones in the environment and food samples are concerning and pose a threat. Opto-electrochemical sensors have received attention due to their low cost, portability, sensitivity, analytical performance, and ease of deployment in the field as compared to conventional expensive technologies that are time-consuming and require experienced professionals. Metal-organic frameworks (MOFs) with variable porosity, active functional sites, and fluorescence capacity are attractive materials for developing opto-electrochemical sensors. Herein, the insights into the capabilities of electrochemical and luminescent MOF sensors for detection and monitoring of antibiotics and hormones from various samples are critically reviewed. The detailed sensing mechanisms and detection limits of MOF sensors are addressed. The challenges, recent advances, and future directions for the development of stable, high-performance MOFs as commercially viable next-generation opto-electrochemical sensor materials for the detection and monitoring of diverse analytes are discussed.

High luminescent N,S,P co-doped carbon dots for the fluorescence sensing of extreme acidity and folic acid

Carbon dots are popular luminescent materials because of their excellent fluorescence properties, but the low quantum yield limits their application. Heteroatom doping is a more convenient and popular approach to increase the quantum yield of carbon dots. Here, novel N,S,P heteroatom co-doped carbon dots (N,S,P-CDs) were synthesized by a simple one-step hydrothermal method using m-phenylenediamine, L-cysteine and phosphoric acid as raw materials. The as-prepared N,S,P-CDs showed excellent photoluminescence properties with a fluorescence quantum yield of up to 41%, which greatly encourages their application in fluorescence sensing. The N,S,P-CDs exhibited good fluorescence stability under salt solution, xenon lamp irradiation and ultraviolet lamp irradiation except for a high sensitivity to extreme acidity. The fluorescence intensity of the N,S,P-CDs can be decreased by as much as 85% when the pH of the solution changes from 2.50 to 4.75, that is, a small fluctuation in pH can cause an intense response of the fluorescence of the N,S,P-CDs. Therefore, an excellent fluorescence sensing platform for accurately monitoring the pH of extreme acidity has been constructed. In addition, the N,S,P-CDs can be applied for quantitative detection of folic acid based on the strong quenching effect of folic acid on the fluorescence of the N,S,P-CDs. Good linearity was obtained in the concentration range of 4.85-82.45 μM, with a detection limit of 0.148 μM. The constructed sensing platform was used for the determination of folic acid in actual samples of orange juice, oatmeal and tablets with satisfactory results.

Terbium(iii)-based coordination polymer with millimeter-size single crystals and high selectivity and sensitivity for folic acid

Terbium(iii)-based coordination polymer with millimeter-size single crystals and high selectivity and sensitivity for folic acid.

A red luminescent europium metal organic framework (Eu-MOF) integrated with a paper strip using smartphone visual detection for determination of folic acid in pharmaceutical formulations

Integration of smartphone with visual-based paper strip as a low-cost, fast, and reliable probe for semi-quantitative analysis of folic acid.