About 4-hydroxyethyl-piperazine ethanesulfonic acid (HEPES), those applications you don’t know

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The biological buffer HEPES has many applications. We are familiar with cell culture medium, pH buffer, redox research and other applications. Next, we will introduce its electrons in the Cu(II)-SA complex. What are the applications of transfer and metal ion research?

The presence of HEPES buffer doubles the reduction current of the Cu(II)-SA complex

Various electrochemical techniques are used to perform measurements on the Hanging Mercury Drop Electrode (HMDE). The presence of HEPES buffer (pH 8.0) doubles the reduction current of the Cu(II)-SA complex, and the reduction potential shifts to a corrected value (approximately 50 mV). The results show that the presence of HEPES buffer promotes the electron transfer between the mercury electrode and the adsorbed Cu(II)-SA complex during the reduction process. Experiments using the two-step potentiometric chronocoulometric method showed that the surface coverage of the Cu(II)-SA complex remains unchanged (between 9 and 10.5 × 10-11 mol cm-2) regardless of the presence of HEPES buffer .

HEPES played an important role in the preparation of Fe3O4 nanoparticles

Studies have found that HEPES plays an important role in the preparation of Fe3O4 nanoparticles, and HEPES can be used as a weak antioxidant to prevent the complete oxidation of Fe(II) to Fe(III). In the reaction system, the influence of inorganic anions on the morphology of Fe3O4 nanostructures was also studied. The synthesized spherical Fe3O4 nanoparticles have a concentration of 5-100 μg mL-1 and are non-toxic to normal HUVEC cells, indicating their potential applications in biology. Combined with the preparation of Ag and Au nanoparticles in HEPES solution, Ag/Fe3O4 and Au/Fe3O4 nanocomposites were successfully synthesized through a two-step method, which has excellent antibacterial properties against Staphylococcus aureus. In addition, Ag/Fe3O4 and Au/Fe3O4 nanocomposites can be recycled and reused due to their superparamagnetic and antibacterial activity.

HEPES can inhibit the fibril elongation process of hCT

A transmission electron microscope was used to examine the fibrillation process in the HEPES solution. It was found that the fibrosis rate of hCT in HEPES solution was much lower than that of phosphate buffer and acetic acid solution. Spherical intermediate aggregates were observed in the early stages of fibril formation, and short fibrils appeared on the surface of the spherical intermediate. Subsequently, the spherical intermediate is directly transformed into long fibrils, and then elongated into mature hCT fibrils. The kinetics of fibril formation was examined based on the two-step autocatalytic reaction mechanism. The first step nucleation rate (k1) in HEPES solution is lower than in phosphate buffer and acetic acid solutions because the half-life of the intermediate is significantly longer in HEPES solution. The specific interaction between HEPES molecules and hCT can stabilize the spherical intermediate, thereby inhibiting the fibril elongation process of hCT.