A colorimetric - ratiometric SERS dual-mode sensor based on magnetic COF nanoflowers is used for the detection of glucose in food.

Accurate and rapid detection of glucose is of great significance for food safety and public health. In this study, we developed an Fe3O4@COF@Au(GOx) substrate based on magnetic COF materials. This substrate exhibits excellent adsorption capacity, enzymatic activity, and surface-enhanced Raman scattering (SERS) enhancement effect. This substrate can trigger a color reaction of 3,3',5,5'-tetramethylbenzidine (TMB) and a change in the signal intensity of SERS when glucose is present. The ethanol Raman signal is used as the ratio signal to achieve the dual detection mode of colorimetric - ratiometric SERS. The dual-mode detection method boasts extremely high sensitivity and excellent selectivity with limits of detection for glucose of 0.17 μM in colorimetric and 10.7 nM in SERS. The dual-mode detection method effectively combines the simplicity of colorimetric detection with the high sensitivity of SERS, providing a highly promising solution for the detection of glucose in practical applications.