A novel wide-range colorimetric glucose biosensor based on enzymatic etching of triangular gold nanosheets

Blood glucose detection is an essential of diabetes management, so it is urgent to develop a convenient and practical blood glucose monitoring method. Herein, a wide range colorimetric assay for the detection of glucose based on enzymatic etching of triangular gold nanosheets was reported. In the presence of glucose oxidase (GOD) catalyzed the oxidation of glucose to produce hydrogen peroxide (H 2 O 2 ), which induced the etching of triangular gold nanosheets (AuTNPs) from triangular to round. The shape and size of the AuTNPs changed. Both enzymatic reaction and H 2 O 2 etching can lead to LSPR displacement. Then the etching mechanism is closely related to the concentration of AuTNPs, the high sensitivity of this assay at low concentration particle AuTNPs. The ratio and concentration of EDC/NHS, pH value of phosphate buffered solution (PBS) and GOD concentration were studied, and the best detection conditions of glucose were determined. Under the optimal detection conditions, this glucose colorimetric sensor exhibits excellent sensing performance in the glucose range of 0.2 to 12 mM and the limit of detection is limit 0.1mM (S/N = 3). In addition, glucose was tested in artificial fluids. The results demonstrated that the colorimetric analysis based on triangular gold nanosheets-glucose oxidase system performs in artificial fluids as well as in phosphate buffer solution, making it very suitable for the clinical diagnosis of diabetes.