Green Synthesis of Porous Spherical Reduced Graphene Oxide and Its Application in Immobilized Pectinase

Abstract

Pectinase is widely used in juice production, food processes, and other fields. However, owing to poor stability, free pectinase is difficult to separate from a substrate after hydrolysis and cannot be reused, and thus its industrial use is limited. Immobilized pectinase can solve these problems well. We prepared a carrier material of immobilized enzyme, which is called porous spherical reduced graphene oxide (rGO) with a rich pore structure, large specific surface area, strong hardness, and good biocompatibility to enzyme. Then, we evaluated the performance of the porous spherical rGO immobilized pectinase and characterized its structure by IR, XRD, and SEM. Using this material as a carrier of immobilized enzyme improves the load and catalytic activity of the enzyme. After 10 times of continuous use, the porous spherical rGO immobilized enzyme still maintained its initial relative enzyme activity at around 87%, indicating that immobilized pectinase had a stronger cycling stability, and its thermal stability, acid–base tolerance, and storage stability were superior to those of free pectinase. The results were compared with those of other studies on immobilized pectinase. The relative activity of pectinase immobilized by porous spherical rGO was at a high level after 10 consecutive uses. Overall, the spherical rGO is an excellent immobilized enzyme carrier material.

Lemon Juice Assisted Green Synthesis of Reduced Graphene Oxide and Its Application for Adsorption of Methylene Blue

“…The discovery of graphene [1] changed the scenario of the research world of nanomaterials. Graphene and its derivatives have become one of the most fascinating and hottest research topics in the empire of carbon nanomaterials [1][2][3][4][5][6][7][8][9], because of their versatile properties like high surface area, high mechanical strength, and excellent electrical and thermal conductivities, and promising applications in the field of material science and engineering, including energy storage, catalysis, drug delivery, sensing and biosensing, and water treatment [10][11][12][13][14][15][16][17][18] Various methods have been employed to produce graphene and its analogue, reduced graphene oxide (rGO). In particular, chemical reduction of exfoliated graphene oxide (GO) is efficient and advantageous in the large-scale production of rGO, because high-quality rGO with a relatively lower oxygen content can be obtained at a low cost in a short time [19,20].…”

Near Green Synthesis of Porous Graphene from Graphite Using an Encapsulated Ferrate(VI) Oxidant

“…Figure presents together the transmittance FT-IR spectra of bare and encapsulated K 2 FeO 4 . In the case of the former (Figure a), a primary peak appeared at 808 cm –1 along with a shoulder peak at 780 cm –1 , which was the characteristic peak of FeO 4 . − In the case of the latter (Figure b), the spectrum showed the characteristics peaks of the shell materials. The characteristic peak at 1100 cm –1 arose from ethyl cellulose, and those centered around 2916, 1471, and 720 cm –1 belong to the stretching and bending vibrations of paraffin wax .…”

“…The emissions from it largely impact water toxicity and could give cancerous effects on humans . Gao et al suggested that l -ascorbic acid (vitamin C) is an excellent alternative for hydrazine in the reduction of GO. , Unlike hydrazine, l -ascorbic acid is environmentally friendly and does not cause any ill effects in human respiratory organs. , Zengin Kurt et al compared the effects of several reducing agents extracted from plants such as cloves, white mulberry, black cumin seed, blackthorn, dark grape, and rosehip on the synthesis of PG materials. However, all these relatively green techniques are only applicable to the synthesis of PG from a GO precursor.…”

Green syntheses of graphene and its applications in internet of things (IoT)—a status review

“…In some variations, the reducing agents are first mixed with graphite powder, followed by ball-milling to obtain GO, which is then further reduced to RGO [71]. Also, few groups prepared graphene (or RGO) from graphite using L-ascorbic acid and L-arginine as reducing agents, which are mild, nontoxic, environmentfriendly alternatives for conventional reducing agents [75][76][77][78][79].…”