Yiran Wang,Xiaolong Sun,Yufeng Zhou,Jiachen Liu,Huayue Zhu,Ru Jiang,Yingjie Miao,Yongqian Fu
Quercetin (QCT) is a flavonoid with significant health benefits, necessitating sensitive detection methods for food safety and quality control . This study presents a novel UiO-66-TCPP ratiometric fluorescent probe for the quantitative and visual detection of QCT. Under optimal conditions, the fluorescence intensity of UiO-66-TCPP decreased linearly with increasing QCT concentration, with a detection limit of 26 nM. The probe demonstrated high specificity, showing no significant interference from various substances and QCT analogues. Practical applicability was confirmed by testing artificially contaminated juice samples, achieving recovery rates between 98.0% and 104.8%. Furthermore, a paper-based sensor was developed by incorporating UiO-66-TCPP onto Whatman#1 chromatography paper . This sensor exhibited stable fluorescence and a reliable, sensitive visual response to QCT concentrations, detectable via a smartphone-based color recognizer application. The UiO-66-TCPP ratiometric fluorescent probe provides a sensitive, specific, and practical method for detecting QCT in food matrices, offering significant potential for both laboratory and on-site applications.
Patulin (PAT) is a potentially harmful mycotoxin to human health and is known to contaminate apple juice. In this work, we developed a ratiometric fluorescence aptasensor using tetrakis(4-carboxyphenyl)porphyrin (H 2 TCPP)-treated octahedral UiO-66-NH 2 (defined as UiO-66-TCPP) to detect PAT. This 2-aminoterephthalic acid and H 2 TCPP functionalized metal-organic framework showed multiple adsorption effects (hydrogen bonding and π–π stacking) on the aptamer (Apt) and served as a quenching material. When the target PAT bound specifically to the Apt, the fluorescence of the 6-carboxyfluorescein-labeled Apt would recover, and the fluorescence of the H 2 TCPP ligand remained unchanged. This ratiometric fluorescence property improved the accuracy of PAT detection. Moreover, the introduction of the H 2 TCPP ligand enhanced the quenching efficiency of UiO-66-NH 2 , thus improving the sensitivity of the fluorescent aptasensor (UiO-66-TCPP vs. UiO-66-NH 2 : 0.0162 ng/mL vs. 1.8 ng/mL). In addition, we used UiO-66-TCPP to detect PAT in apple juice samples. This work provides a good paradigm for the construction of ratiometric fluorescence aptasensors with high sensitivity and accuracy.
Chenglin Zhang,Ya Wang,Qian Zhang,Baolian Liu,Xiupei Yang
The accurate determination of β-Lactoglobulin (β-LG), a major dairy allergen, is essential for susceptible individuals' health. Here, a multimodal β-LG sensor was developed by utilizing the aptamer (Apt) to regulate the metal-organic framework UiO-66-TCPP’ functions. The prepared UiO-66-TCPP had both fluorescence and peroxidase activity. After adsorbing β-LG Apt, the catalytic activity of UiO-66-TCPP was enhanced through increased substrate affinity and electron transfer, while the fluorescence of 6-carboxyfluorescein-labeled Apt was quenched via multiple interactions with the material, and the fluorescence of UiO-66-TCPP itself remained unchanged. After binding to β-LG, Apt desorbed from UiO-66-TCPP surface, thereby restoring Apt fluorescence and lowering UiO-66-TCPP’ catalytic activity. Thus, a colorimetric/ratiometric fluorescence platform for β-LG sensing in dairy products was constructed with low limits of detection (16.19, 47.69 ng/mL). On-site visual detection was further achieved by RGB analysis on a smartphone. This study proposes novel approaches to creating multi-modal platforms for accurate food allergen determination.
危险品化学品经营许可证（带存储）