Graphene Oxide Membrane Immobilized Aptamer as a Highly Selective Hormone Removal

Abstract

Three-dimensional (3D) reduced graphene oxide (rGO) modified by polyethyleneimine (PEI) was prepared and functionalized by fluorophore-labeled dexamethasone-aptamer (Flu-DEX-apt) via π–π stacking interaction. The rGO/PEI/Flu-DEX-apt was used as a selective membrane for dexamethasone hormone removal from water. The prepared rGO/PEI/Flu-DEX-apt membranes were stable, insoluble, and easily removable from liquid media. The membrane was characterized by Raman spectroscopy, scanning electron spectroscopy, and FTIR spectroscopy. The rGO/PEI/Flu-DEX-apt membrane showed high sensitivity and specificity toward the dexamethasone hormone in the presence of other steroid hormone analogs, such as progesterone, estrone, estradiol, and 19-norethindrone. The fluorescence and UV–visible spectroscopy were used to confirm the membranes performance and the quantification of hormones removal. The resulting data clearly show that the graphene oxide concentration influence the aptamers and analytes interaction (π–π stacking interaction). It was found that by varying the graphene oxide concentration yields to different porosities of rGO/PEI/Flu-DEX-apt membranes affects the adsorption recovery rate, as well as the specificity and selectivity toward the dexamethasone hormone.

Nanoporous Graphite-like Membranes Decorated with MoSe2 Nanosheets for Hydrogen Evolution

“…Subsequently, 15% w/v gelatin was dissolved in 1.5 mg mL –1 graphene oxide solution, and the resulting solution was stirred until a stable aqueous suspension was obtained: Scheme a. The mixture was precooled at 4 °C for 15 min before adding the cross-linking agent glutaraldehyde at 10% v/v. , The solutions were then poured into a rectangular mold and placed in a cryostat at −76 °C for 16 h; Scheme b. The prepared gelatin hydrogel underwent a freeze-drying process for more than 12 h at −76 °C to form a 3D structure (VirTis Freezemobile 25L, SP Scientific, WA, USA): Scheme c.…”

Selection of Highly Specific Aptamers by Graphene Oxide-SELEX to Ultrasensitive Label-Free Impedimetric Biosensor Development for Glyphosate Detection

“…Phosphate-buffered saline pH 7.4 (PBS), potassium ferrocyanide (K 4 Fe­(CN) 6 ), potassium ferricyanide (K 3 Fe­(CN) 6 ), and magnesium chloride (MgCl 2 ), were purchased from Sigma-Aldrich (Oakville, ON, CAN) at ≥98.5% purity. GO was synthesized following a modified Hummer’s method, as reported by our group. , The obtained graphene oxide was characterized by different methods including FT-IR, atomic force microscopy, Raman spectroscopy, and scanning electron microscopy (see Supporting Information). The used homogeneous GO solution (5 mg/mL) was prepared by stirring and sonication.…”

“…GO was synthesized following a modified Hummer's method, as reported by our group. 39,40 The obtained graphene oxide was characterized by different methods including FT-IR, atomic force microscopy, Raman spectroscopy, and scanning electron microscopy (see Supporting Information). The used homogeneous GO solution (5 mg/mL) was prepared by stirring and sonication.…”

Reduced Graphene Oxide-Based Foam as an Endocrine Disruptor Adsorbent in Aqueous Solutions

“…These composite materials were synthesized in order to enhance mechanical, electrical or structural properties of the polymers. Graphene oxide can be used for preparation of thin conductive films by using various deposition techniques, [20][21][22][23][24] fabrication of electrochemical sensors and biosensors [25,26], preparation of 3D graphene oxide assembly for dyes and gas adsorption [27,28], and as an electrode for energy storage applications like supercapacitors [29,30]. Researchers have worked toward investigating and developing models for understanding the adsorption mechanism of large macromolecules.…”