TMB-AgNPs@COF based SERS probe for the rapid detection of glucose in drinks

Abstract

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.