Improved Performance of Lipase Immobilized on Tannic Acid-Templated Mesoporous Silica Nanoparticles

Abstract

Mesoporous silica nanoparticles were synthesized by using tannic acid as a pore-forming agent, which is an environmentally friendly, cheap, and non-surfactant template. SEM and TEM images indicated that the tannic acid-templated mesoporous silica nanoparticles (TA-MSNs) are monodisperse spherical-like particles with an average diameter of 195 ± 16 nm. The Brunauer-Emmett-Teller (BET) results showed that the TA-MSNs had a relatively high surface area (447 m(2)/g) and large pore volume (0.91 cm(3)/g), and the mean pore size was ca. 10.1 nm. Burkholderia cepacia lipase was immobilized on the TA-MSNs by physical adsorption for the first time, and the properties of immobilized lipase (BCL@TA-MSNs) were investigated. The BCL@TA-MSNs exhibited satisfactory thermal stability; strong tolerance to organic solvents such as methanol, ethanol, isooctane, n-hexane, and tetrahydrofuran; and high operational reusability when BCL@TA-MSNs were applied in esterification and transesterification reactions. After recycling 15 times in the transesterification reaction for biodiesel production, over 85 % of biodiesel yield can be maintained. With these desired characteristics, the TA-MSNs may provide excellent candidates for enzyme immobilization.

Dopamine functionalized tannic-acid-templated mesoporous silica nanoparticles as a new sorbent for the efficient removal of Cu2+ from aqueous solution

“…However, this synthetic method of MSNPs has several disadvantages as following: (1) the surfactants are expensive and toxic; (2) the calcinations used to remove the surfactants may lead to the reduction of the amount of silanol groups on the surface of MSNPs because of the high-temperature. Hence, a non-toxic, low-cost and especially nonsurfactant templating method that utilized to synthesize MSNPs with interconnected pores is highly required 21 .…”

“…Jiang et al . synthesized TA-MSNs with TA as the template, and then the TA-MSNs were used as the supports for BCL immobilization 21 .…”

Biomimetic-Functionalized, Tannic Acid-Templated Mesoporous Silica as a New Support for Immobilization of NHase

“…After recycling for 8 batches, the relative activity ofNHase@TAMS and NHase@Dop-TAMS was found to be 52.4% and 62.2%, respectively. The activity loss for the enzyme can be primarily attributed to leakage of NHase from the carrier and denaturation of the NHase molecules [ 19 , 23 ]. Compared with the NHase@TAMS, the activity of NHase@Dop-TAMS decreased slowly, and the improved operational stability of NHase@Dop-TAMS can be ascribed to the strong conjugation of covalent bonds between the NHase molecules and the polydopamine on the surface of Dop-TAMS, which could have prevented the leakage of NHase from the NHase@Dop-TAMS [ 36 ].…”

“…The resulting product was denoted as NHase@Dop-TAMS, which was stored in PBS at 4 °C until use. The quantity of NHase in the solution was measured by Bradford assay and the loading amounts of NHase in the matrix were calculated [ 23 ]. NHase was also immobilized in TAMS by physical adsorption (named NHase@TAMS), in order to make comparisons with the NHase@Dop-TAMS.…”

“…Recent research has found that tannic acid may be a suitable template agent. Tannic acid is a class of polyphenol compound with complex structure and is found in numerous plants [ 22 , 23 ]. It is not only cheap and environmental friendly, but can also be dissolved in water or alcohol.…”