MIL-53(Fe) MOF-mediated catalytic chemiluminescence for sensitive detection of glucose

Various analytical applications of metal-organic frameworks (MOFs) have been rapidly developed in the past few years. However, the employment of MOFs as catalysts in chemiluminescence (CL) analysis is rare. Here, for the first time, we found that MIL-53(Fe) MOFs could significantly enhance the CL of luminol in the presence of H2O2 in an alkaline medium. The CL intensity in the luminol-H2O2-MIL-53(Fe) system was about 20 times higher than that in the luminol-H2O2 system. Moreover, the XRD pattern of MIL-53(Fe) after CL reaction was almost the same as that of the original MIL-53(Fe), confirming the catalytic role of MIL-53(Fe) in the luminol-H2O2-MIL-53(Fe) system. The possible mechanism behind the enhancing phenomenon was discussed based on the results from the CL spectra, FL probe experiments, and active oxygen species measurements. By coupling with the glucose oxidase-based catalytic oxidation reaction, a sensitive and selective CL method was developed for the detection of glucose. There is a linear relationship between the logarithm of CL intensity and the logarithm of glucose concentration in the range from 0.1 to 10 mu M, and a detection limit of 0.05 mu M (S/N = 3) is obtained. The proposed method has been applied to the determination of glucose in human serum samples with satisfactory results.