Colorimetric detection of glucose using lanthanum-incorporated MCM-41.

In this study, lanthanum-containing mesoporous MCM-41 (La-MCM-41) with different amount of lanthanum were synthesized and were used for colorimetric detection of glucose. As prepared La-MCM-41 were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The quantitative amounts of incorporated lanthanum into MCM-41 structure were estimated by energy dispersive X-ray spectrometry. The prepared La-MCM-41 provided high intrinsic peroxidase-like activity in the presence of peroxidise 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 for accurate determination of glucose. This process produced a blue color in aqueous solution that directly relates to H2O2 concentration. The effect of different parameters such as the content of incorporated lanthanum, pH, temperature and time of reaction on the peroxidase-like activity was studied. The colorimetric detection of H2O2 was led to a linear dynamic range from 50 to 1000 μM (r2 = 0.9988) and low detection limit of 37.5 μM for glucose in aqueous solution. These results are comparable (close to) or better than some previous reports. Thus, La-MCM-41 can be used as admirable alternative design for colorimetric sensing of glucose.