Graphene Oxide For Selective Detection Research Articles

An electrochemical sensor based on molecularly imprinted polydopamine coated on reduced graphene oxide for selective detection of ornidazole

AbstractThe electrochemical sensing of ornidazole (OR) was achieved with a highly selective sensor fabricated by a combination of an electrochemically reduced graphene oxide (ERGO) and molecularly imprinted polydopamine (PDA). The sensor (OR‐imp@PDA/ERGO/GCE) was synthesized by electrochemical polymerization of dopamine (DA) on ERGO modified glassy carbon electrode (GCE). The analytical response of the sensor changed linearly with OR concentration varying from 1.5 × 10−9 M to 1.0 × 10−8 M and 1.0 × 10−8 M to 2.0 × 10−7 M, and the detection limit was defined as 1.1 × 10−9 M. The proposed sensor ensured the highly sensitive detection of OR concentration because of the advantages of ERGO and molecularly imprinted PDA.

A surface plasmon resonance sensor with synthetic receptors decorated on graphene oxide for selective detection of benzylpenicillin

Antibiotic residues in foods, water and the environment reveal antibiotic-resistant bacterial strains, disrupting the ecological balance and causing serious health problems. For these reasons, the detection of antibiotic residues is crucial for the protection of human health. Herein, the detection of benzylpenicillin antibiotic from aqueous and milk sample solutions was carried out by surface plasmon resonance (SPR) sensor using synthetic receptor-molecularly imprinted polymer. The benzylpenicillin-imprinted poly(hydroxyethyl methacrylate-graphene oxide-N-methacryloyl-l-phenylalanine) (MIP-GO) SPR sensor was prepared. Benzylpenicillin detection was performed by MIP-GO SPR sensor in a 1–100 ppb concentration range of benzylpenicillin with 0.9665 linear correlation and 0.021 ppb detection limit. Selectivity analysis showed that the MIP-GO SPR sensor detected the benzylpenicillin molecule 8.16 times more selectively than amoxicillin and 14.04 times more selectively than ampicillin. To examine the imprinting efficiency, non-imprinted poly(hydroxyethyl methacrylate-graphene oxide-N-methacryloyl-l-phenylalanine) (NIP-GO) SPR sensor was also prepared using the same procedure without benzylpenicillin addition. Since graphene oxide (GO) was added to enhance the sensor signal response by increasing sensitivity, the control analyses were performed by a poly(hydroxyethyl methacrylate-N-methacryloyl-l-phenylalanine) (MIP) SPR sensor without adding GO. Moreover, repeatability studies of MIP-GO SPR sensor were statistically evaluated and the RSD of intra-day assays less than 1% specified that there was no loss of performance for the benzylpenicillin detection ability even after four cycles. As a real food sample analysis, the benzylpenicillin spiked and unspiked milk samples were evaluated and high-performance liquid chromatography experiments were carried out for validation.

Highly fluorescent hematoporphyrin modified graphene oxide for selective detection of copper ions in aqueous solutions

Here, a highly sensitive and selective copper ion (Cu2+) fluorescence sensor is reported. The Hematoporphyrin functionalized Graphene Oxide (HP-GO) fluorescence sensor were synthesized via esterification reaction between Graphene Oxide and Hematoporphyrin (HP). The HP-GO sensor was fully characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electrom Microscopy (SEM), UV–Vis spectroscopy, Transmission Electron Microscopy (TEM), Fluor meter spectroscopy, X-Ray photoelectron spectroscopy(XPS), and Raman spectroscopy measurements. The HP-GO sensor advertised two linear regions over the range of 0–1.18 × 103 nM and 3.93 × 103 to 47.27 nM of copper (II) with detection limit of 54 nM in the aqueous solution. The selectivity of HP-GO for Cu2+ is much higher than that of other metal ions due to the presence of aza macrocyclic ring on the surface of HP-GO which has a high binding affinity with Cu2+. Additionally, the HP-GO shows wide pH viable range (pH 6–10). The effect of other metal ions on the fluorescence intensity of the HP-GO was also studied and other metal ions show a low interference response in the detection of Cu2+. HP-GO sensor manifests advantages of high reproducibility (The quenched fluorescence of HP/GO-Cu can be recovered by EDTA), attractive long term fluorescence stability (>21 days) in water, also remarkable selectivity regarding number of metal ions (Na+, K+, Ca2+, Fe3+, Fe2+, Al3+, Pb2+, Mn2+, Mg2+, Co2+, Ni2+, Cr6+, Cd2+, Hg2+, and Zn2+), low toxicity and can detect Cu2+ in real water samples which acquire well for its promising in environmental applications.

Facile synthesis of cellulose microfibers supported palladium nanospindles on graphene oxide for selective detection of dopamine in pharmaceutical and biological samples

The cost-effective synthesis of novel functional nanomaterials has received significant attention in the physical and chemical sciences due to their improved surface area, high catalytic activity along with unique morphological features. This paper reports a facile and eco-friendly synthesis of spindle-like palladium nanostructures (PdSPs) on graphene oxide-cellulose microfiber (GO-CMF) composite for the first time. The GO-CMF/PdSPs composite was synthesized by an electrochemical method without the use of additional surfactants and capping agents. The synthesized materials were characterized and confirmed by using transmission electron microscopy, high-resolution scanning electron microscopy, X-ray diffraction spectroscopy, Raman spectroscopy and Fourier-transform infrared spectroscopy. As-synthesized GO-CMF/PdSPs composite modified electrode was used as a selective electrocatalyst for the oxidation of dopamine (DA). The electrochemical redox behaviors of DA were investigated using cyclic voltammetry (CV). The CV results revealed that the GO-CMF/PdSPs composite modified electrode has 10 folds enhanced oxidation current response to DA than GO, PdSPs and GO-CMF modified GCEs. Under optimized conditions, the GO-CMF/PdSPs composite sensor exhibits a linear response to DA in the concentration range from 0.3 to 196.3 μM with the lower detection limit of 23 nM. The nanocomposite electrode also shows promising features towards the reliable and selective detection of DA, which includes high stability, reproducibility and high selectivity towards the commonly interfering species such as ascorbic acid, uric acid, and dihydroxybenzene isomers. The sensor was successfully tested for the real-time detection of DA in the commercial DA injections and human serum samples.

Fabrication of 1,4-bis(aminomethyl)benzene and cobalt hydroxide @ graphene oxide for selective detection of dopamine in the presence of ascorbic acid and serotonin

A simple electrochemical sensor for detecting dopamine was fabricated using 1,4-bis(aminomethyl)benzene (BAMB) and cobalt hydroxide (Co(OH)2) at graphene oxide (GO) surface using a simple solution-based chemical reduction method. The successful formation of GO-BAMB-Co(OH)2 was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy, while the electrochemical performance of the material was studied using different techniques, including cyclic voltammetry, differential pulse voltammetry, linear sweep voltammetry, and chronoamperometry in 0.1M PBS at pH 7.4. The GO-BAMB-Co(OH)2-modified electrode showed an excellent electrochemical response with a broad linear range (3–20 and 25–100μM) and low limit of detection (0.4μM). Furthermore, efficient selective detection of dopamine in the presence of a 10-fold excess concentration of bio-interfering species, such as ascorbic acid and serotonin, was remarkable. The practical feasibility of the sensor was checked using urine samples, which showed appreciable recovery results. The main advantages of this sensor are its simple electrode fabrication procedure, rapid sensing response, remarkable selectivity, repeatability, and stability.

A promising electrochemical sensor based on Au nanoparticles decorated reduced graphene oxide for selective detection of herbicide diuron in natural waters

In this study, an electrochemical sensor for the detection of herbicide diuron in natural water using a reduced graphene oxide–gold nanoparticle (rGO–AuNP)-modified screen-printed electrode (SPE) was developed. The proposed sensor was fabricated by the simple electrochemical co-reduction of graphene oxide and chloroauric acid using a cyclic voltammetry (CV) technique and applied to the direct electrochemical detection of diuron residue in water without using any mediator. A field emission scanning electron microscope image showed that the AuNPs were firmly attached and well distributed on the surface of the rGO nanosheets. The presence of rGO nanosheets was further proven by the Raman spectrum, which reveals that the D/G intensity ratio for rGO was smaller than that for GO. Moreover, the CV and linear sweep voltammetry results showed the effective accumulation of diuron on the rGO–AuNP/SPE surface and produced an irreversible reduction peak at around −0.5 V in a pH 5.5 phosphate buffer. Hence, it greatly enhanced the electrochemical reduction of diuron. Under optimized conditions, the cathodic peak current was proportional to the diuron concentration over a wide range of 0.5–30.0 µg mL−1, with a detection limit of 0.125 µg mL−1 (S/N = 3). The proposed diuron electrochemical sensor also exhibited a relative standard deviation of 4.25 % for a six replicate analysis of 10.0 µg mL−1 diuron, and the response of the electrode declined by 20 % after 30 days at ambient temperature. In addition, the sensor was successfully employed for the determination of diuron in a variety of water samples such as lake and seawater sample.

Chemically-modulated photoluminescence of graphene oxide for selective detection of neurotransmitter by "turn-on" response.

Designing artificial nanomaterials capable of selectively detecting targets without the use of expensive and fragile antibodies is of great interest in the applications of nanomedicine. Here, we show that the photoluminescence (PL) of graphene oxide (GO) was chemically modulated for the selective detection of a neurotransmitter without the use of antibodies. GO was functionalized with nitrotriacetic acid (NTA) on which four different metal ions were chelated (M-NTA-GO), which led to its different PL responses to neurotransmitters. In particular, the Cu-NTA-GO hybrid was able to selectively detect norepinephrine at nanomolar concentrations in a simple manner via its "turn-on" PL. Moreover, it was successfully applied to the selective detection of norepinephrine secreted from living PC-12 cells.

One-step synthesis of porous cuprous oxide microspheres on reduced graphene oxide for selective detection of mercury ions

A facile one-step synthesis of Cu2OMS–rGO nanocomposites used as a sensitive layer for selective detection of mercury ions was reported.

Optical Turn-On Sensor Based on Graphene Oxide for Selective Detection ofd-Glucosamine

By incorporating the well-known fluorophore 8-aminoquinoline into graphene oxide, we have successfully prepared a turn-on fluorescent sensor capable of specific detection of D-glucosamine with a high selectivity and sensitivity. This methodology provides a new concept for the design and development of highly selective and sensitive turn-on optical sensors for selective detection of aminosaccharides and many other biomolecules.