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As a dihydrochalcone natural sweetener extracted from Lithocarpus litseifolius , trilobatin is an emerging functional sweetener in the international arena in recent years and is gaining attention in the food industry. The detection of trilobatin has also gradually received the attention of researchers, however, the detection means for trilobatin still remain in the traditional high performance liquid chromatography (HPLC) and other traditional methods, which are costly and have a large detection range. In this work, a method based on the principle of surface-enhanced Raman (SERS) using a composite substrate of silver nanoparticles (Ag NPs) and covalent organic frameworks (COFs) materials is proposed for the detection of trilobatin in tea beverages. After Gaussian simulation and a series of spectral analysis methods for validation, the functionalized SERS substrates contain abundant hydroxyl groups on the surface, which can be combined with trilobatin through hydrogen bonding and greatly enhance the Raman signal of trilobatin. The specific detection of trilobatin in tea beverages has been realized and the problem of weak SERS signal of trilobatin in liquid environment has been solved. The limit of detection (LOD) of trilobatin in tea beverage was 2.8 nM, and the correlation coefficient (R2) was 0.995. The recoveries were in the range of 100.6∼106.0% with the RSD of 1.756∼4.921%. In conclusion, the experimental method is highly sensitive and specific, and can realize the nondestructive detection of trilobatin in samples with high practical value. [Display omitted] • First SERS-based method for the detection of trilobatin in beverages using Ag@COF substrates. • This method can be applied in the detection of real drink samples without pretreatment procedures. • The detection time of the substrate to the sample is short and the recovery rate is high. [ABSTRACT FROM AUTHOR]

The detection of glucose in drinks (especially for sugar-free drinks) is of great practical significance. The traditional method for the detection of glucose was based on an enzymatic reaction using glucose oxidase, which takes a long time. Herein, a TMB-AgNPs@COF based SERS probe was designed for the rapid detection of glucose in drinks. The SERS probe was fabricated using silver nanoparticles loaded covalent organic frameworks (COFs) as substrate, 3,3',5,5'-Tetramethylbenzidine (TMB) was introduced as a signal molecule to solve the problem of weak SERS signal of glucose. The fabricated SERS probe is denoted as TMB-AgNPs@COF. The detection mechanism was based on the competitive binding of TMB and glucose with AgNPs@COF substrate. Glucose was more likely to bond with the substrate which was verified by Gaussian theory simulation. The SERS signal of TMB gradually decreased when glucose was introduced. The interaction between the substrate and glucose can also be demonstrated by SERS spectroscopy. By applying this method, we could achieve the detection limit of 0.096 μg/mL in drinks. The relative standard deviations were 2.63 %− 4.89 % in the recovery experiments of drinks. The whole detection time was less than 5 min and the substrate had good reproducibility. Therefore, the method was confirmed with a high potential for the detection of glucose in drinks. [Display omitted] • The TMB-AgNPs@COF was first designed as SERS probe for detection of glucose in drinks. • This method can be applied in the detection of real drink samples without pretreatment procedures. • This method realizes rapid glucose detection in less than 5 min. [ABSTRACT FROM AUTHOR]