The potential of heteropoly acid H 3 PW 12 O 40 to catalyze the hydrolysis of cellulose to glucose under hydrothermal conditions was explored. This technology could contribute to sustainable societies in the future by using cellulose biomass. A study to optimize the reaction conditions, such as the amount of catalyst, reaction time, temperature, and the amount of cellulose used, was performed. A remarkably high yield of glucose (50.5%) and selectivity higher than 90% at 453 K for 2 h with a mass ratio of cellulose to H 3 PW 12 O 40 of 0.42 were achieved. This was attributed to the high hydrothermal stability and the excellent catalytic properties, such as the strong Brønsted acid sites. This homogeneous catalyst can be recycled for reuse by extraction with diethyl ether. The results illustrate that H 3 PW 12 O 40 is an environmentally benign acid catalyst for the hydrolysis of cellulose.

A SERS active gold nanostar layer on the surface of ITO glass slip has been prepared by a low-cost electrostatically assisted APTES-functionalized surface-assembly method for SERS analysis. The two-dimensional morphology of the SERS substrate was examined by scanning electron microscopy. Comparative analysis revealed that the optical characteristics and SERS efficiency of these substrates varied as a function of nanostar morphology. It was found that the substrate assembled with the longest branches of nanostars generated the best SERS efficiency, whether the excitation source is 785 or 633 nm. The potential use of these substrates in detection applications was also investigated by using Nile blue A and Rhodamine 6G. The detection limits are 5 × 10(-11) M and 1 × 10(-9) M, respectively, when using the 785 nm excitation source. Apart from this high enhancement effect, the substrate here also shows extremely good reproducibility at the same time. All of these indicate that gold nanostars are a very good structure for SERS substrate assembly.

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