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Recently, zeolites with two-dimensional structures, so-called nanosheet zeolites, have been intensively advanced owing to their excellent catalytic performance compared to conventional zeolite. This extremely thin nanosheet structure of zeolite provides more accessible active sites contributing to shortened diffusion pathways and primarily enables bulky molecules to undergo catalytic reactions. Several nanosheet zeolites, such as MFI, FAU, MOR, MWW, TS-1, have been successfully synthesized. Generally, they are obtained by direct synthesis method involving surfactant as structure-directing agent (SDA) and or seed. Interestingly, almost every part of the synthesis parameter conditions can alter the characteristics of this nanosheet zeolite. Thus, 2D zeolites also offer easily tunable characteristics. Up to now, nanosheet zeolites have been extensively studied as a catalyst in methanol conversion, catalytic cracking, isomerization, alkylation, oxidation/reduction, lignocellulose conversion, and other reactions. Furthermore, the modification of nanosheet zeolite could be pursued to enhance its catalytic performance. Pillaring is evidently effective in improving the textural properties of nanosheet zeolite by protecting the mesopore structure during the SDA removal. Herein, we comprehensively present the recent progress on the development of nanosheet zeolites. This review concludes with a summary of a discussion of remaining challenges and outlook for nanosheet catalyst technologies.

Cyanides are deadly toxic substances commonly found in cassava root tuber. Higher content of cyanides causes bitter taste of the root tuber. Therefore, analysis of cyanide content has been used as one of criteria for bitterness in cassava. The substitute common method used for this purpose was organoleptic test that could lead to poisoning, or argentometry, which is complicated, time-consuming, and requires lots of reagents. Therefore, a fast, easy, and safe method is strongly demanded. In this work, a smart screening technology kit (SST-Kit) was developed using ninhydrin reagent. This simple, fast, and low-cost method can be applied in the field for the analysis of cyanide levels in cassava. This method was optimized to the concentration of sodium carbonate from 0.5 to 2.0% by measuring the red color intensity produced under various times of reading from 1 to 3 minutes and three sample preparation techniques. The optimum condition for SST-Kit to read the cyanides level was achieved under the condition of 0.5% of sodium carbonate with a time readout of 2 minutes, using grinding preparation technique followed by dilution. The SST-kit had been applied on cassava samples with the accuracy of more than 90%.

The control of uric acid is important. A high level of uric acid can cause gout disease. Therefore a simple, fast, and accurate method for uric acid determination is required. In this research a conductometric biosensor has been developed by SPCE – Nata de coco for uric acid determination. The prepared biosensor was optimized to get a good performance of biosensor and it is applicable for human serum samples. The optimized variables were enzyme concentration, membrane thickness and pH solution. The various enzyme concentration were 6 μg/mL; 12 μg/mL; 18μg/mL; 24 μg/mL. The various membrane thickness were 5 μm; 10 μm; 15 μm. Meanwhile, the various pH solution were 7; 7.5; 8; 8.5; 9. The optimum enzime concentration was 18 µg/mL with the membrane thickness and pH were 5 µm and 8, respectively. The prepared biosensor can determine the uric acid concentration at range of 0 – 1.2 ppm with the sensitivity of 7.74 µS/ppm and the limit detection is 0 ppm. The biosensor was applied to uric acid detection in human serum with accuracy of 95 %.