Almost all processes in a biological cell need enzymes to occur at significant rates. Since enzymes are selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell. Besides their fundamental importance, natural enzymes also have significant practical applications in medicine, chemical industry, food processing, and agriculture due to their excellent properties, such as high substrate specificities and high efficiency under mild conditions. However, natural enzymes also bear some serious disadvantages to limit their practical applications. In general, natural enzymes, which are globular proteins, can be digested by proteases. Like all proteins, the secondary, tertiary, and quaternary levels of enzyme structure are maintained by weak, noncovalent forces and can be easily disrupted by environmental changes, such as heating or chemical denaturants, which leading to the loss of their catalytic activity. Furthermore, preparation, purification, and storage of natural enzymes are usually time-consuming and expensive.

Ultrathin two-dimensional metal–organic frameworks (2D MOFs) have recently attracted extensive interest in various catalytic fields (e.g., electrocatalysis, photocatalysis, thermocatalysis) due to their ultrathin thickness, large surface area, abundant accessible unsaturated...

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Down-regulation of miR-16 plays critical roles in CRC progression. Low miR-16 expression is an independent factor predicting a poor prognosis for CRC patients.

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Fluorescent probes based on boron dipyrromethene functionalized with a phenylboronic acid group (BODIPY-PBAs) were synthesized in high yield for the first time by Suzuki coupling of bis(pinacolato)diboron and 8-(4-bromophenyl)-1,3,5,7-tetramethyl-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY). Wavelength tuning of the fluorophores was achieved by attaching an auxochromic substituent to the 5-position of the BODIPY core structure through Knoevenagel condensation. The emission intensity of fluorophores increases when binding to the analytes with diol groups and forming boronic esters at fixed pH. These compounds can detect monosaccharides in the concentration range of 0.1-100 mM. Whereas glycogen was found to quench the fluorescence of BODIPY-PBAs in an aqueous solution due to the self-quenching of the fluorophores after attaching in the extensively branched and compact glucose polymer, further addition of d-fructose to the solution can release the fluorophores from the polymer and the fluorescence regains. The BODIPY-PBA fluorophore has been applied in polymeric optodes containing anion exchangers to perform repetitive measurement. Such sensors respond to different monosaccharides in the range of 0.1-100 mM and demonstrate an improved selectivity toward d-fructose over other saccharides, compared to the results obtained from homogeneous assay.