Pore Size Tunable Trypsin@ZIF-90 and Hydrogel Integrated Lateral Flow Point-of-Care Platform for ATP Detection.

The cost-effective, convenient, visible, and equipment-free determination of biomarkers is always the priority development concern of disease diagnosis. The paper-based signal output strategy permits output visual signals without instruments and is regarded as a promising approach with simple operation and low cost. Herein, by varying the addition amount of trypsin, we pioneered a novel enzyme mineralization strategy to construct trypsin@ZIF-90 with tunable porosity properties and catalytic activity. The successful synthesis of trypsin@ZIF-90, which is tagged with T1, T3,... (Tx, x is the addition amount of trypsin. Unit: mg), demonstrated the feasibility of this strategy. By serving the constructed trypsin@ZIF-90-T1 as the target recognition module, and a new designed hydrogel-integrated pH indicator strip as the signal reporter, a point-of-care test (POCT) platform was developed for convenient and equipment-free measurement of adenosine triphosphate (ATP). The enzymatic activity measurement of trypsin@ZIF-90 and concurrently the quantitative analysis of ATP can be favorably realized by simple counting the flow distance and coverage area of water released during the reaction on a pH indicator strip. As a result, this portable platform can enable rapid detection of ATP in the linear range of 20-1500 µM and possesses favorable sensitivity, selectivity, and applicability. Thus, the constructions of tunable frameworks and paper-based POCT are of outstanding significance in the fields of porous metal-organic framework synthesis, enzyme mineralization, and rapid detection for medical diagnostics and environmental monitoring applications.

A dual-channel probe based on copper ion-mediated metal organic framework composite for colorimetric and ratiometric fluorescence monitoring of glyphosate degradation in soil and water.

A dual-channel probe was developed, based on a novel composite metal organic frameworks (ZnMOF-74@Al-MOF) for glyphosate determination through ratio fluorescence and colorimetric methods. The prepared probe can not only recognize and combine glyphosate by introducing copper ion into the MOF, but also possess peroxidase-like catalytic activity. The recognition of target glyphosate brought about changes relative to its concentration on fluorescence intensity and ultraviolet absorption. And, the high specific surface area and porosity of porphyrin MOF provides the developed probe with more response opportunities to afford a better detection performance for glyphosate. Under optimum conditions, the copper ion-mediated method exhibited good detection performance for glyphosate with low detection limits (0.070 and 0.092 µg mL-1 for fluorescence and colorimetric techniques, respectively). Furthermore, the possible mechanisms of the fluorescence quenching and the peroxidase-like catalytic of the probe were also explored. This dual-channel method was applied to monitor glyphosate degradation in environmental samples and satisfactory results were obtained.