Carbon Ionic Liquid Electrode Research Articles

Application of Graphdiyne Confined Gold Nanoparticles Modified Electrode as A Robust Sensing Platform for The Detection of 7-Hydroxy-6-Methoxy-Hydrocoumarin

A graphdiyne (gdy) and gold nanoparticles (aunps) nanocomposite was formed with aunps growing on the surface and between the layers of gdy, which was used as the sensing interface on carbon ionic liquid electrode (cile) to detect 7-hydroxy-6-methoxy-hydrocoumarin (7–6-hdc) that isolated from the noni juice. The GDY-Au nanocomposite was characterized by different spectroscopic techniques, which exhibited corrugated and folded morphology with large specific surface area. The GDY-Au nanocomposite modified electrode displayed excellent performance which is attributed to the highly conductive nanocomposite, where gdy structure with defects could immobilize more aunps to decrease the electron transfer resistance. In addition, the reaction mechanism of 7–6-hdc at GDY-Au surface was deduced based on the electrochemical kinetics investigations. Combined with density functional theory calculation, it was verified that the active site of 7–6-hdc and the presence of aunps enhanced the electrocatalytic capacity of GDY-Au nanocomposite. Under optimal conditions, the modified electrode displayed a wider linear range from 10.0 nm to 1.0 mm for 7–6-hdc analysis with a detection limit of 3.22 nm (3s0/s). This work provides a promising material to realize accurate analysis for 7–6-hdc, and the discovered sensing mechanism provides method guidance for the exploration of other novel electrochemical sensors.

Electrochemical Determination of Rutin on a Gold Microsphere—Taro Stalk Porous Carbon Modified Carbon Ionic Liquid Electrode (CILE)

As an abundant, inexpensive, and renewable biomass raw material, taro [Colocasia esculenta (L.) Schott] stalks were employed as a simple biochar template due to their porous structure. A composite composed of gold microsphere and taro stalk derived porous carbon (Au-MS@TSPC) was used to construct an electrochemical sensor for the sensitive determination of rutin. Under the optimized conditions, the sensor exhibited a wide linear range from 0.12 to 10.0 μmol·L−1 with a detection limit of 0.0265 μmol·L−1. The sensor demonstrated good selectivity and was applied to the determination of rutin in human serum with recoveries from 94.0% to 105.8%. The fabrication of Au-MS@TSPC in this study provides a promising approach for the subsequent utilization of taro stalks.

Gold nanorods and tungsten disulfide nanocomposite modified electrode for hemoglobin electrochemical biosensing of trichloroacetic acid and nitrite

In this paper, gold nanorods (AuNRs) and tungsten disulfide (WS2) nanocomposite was prepared and modified on the carbon ionic liquid electrode (CILE) surface. Hemoglobin (Hb) was further immobilized on the electrode surface to fabricate a novel modified electrode (Nafion/Hb/AuNRs-WS2/CILE), which exhibited high conductivity and good biocompatibility. The electrochemical behaviors of Hb on the modified electrode were investigated with the appearance of a pair of well-shaped redox peaks, which may be ascribed to direct electron transfer of Hb Fe(III)/Fe(II) redox center. Besides, Nafion/Hb/AuNRs-WS2/CILE showed excellent electrocatalytic activity to the reduction of trichloroacetic acid and nitrite with a wide linear range, and the low detection limit could be obtained as 1.0 mmol/L and 0.33 mmol/L, which extended the application of AuNRs-WS2 nanocomposite in the field of bioelectrochemistry and electrochemical biosensors.

Electrochemical enzyme sensor based on gold-biomass carbon composite modified electrode

In this paper a three-dimensional biomass porous carbon material (WSBPC) was prepared via carbonization combining with KOH activation method by using waste walnut shells as raw materials. Then WSBPC was adopted as a modifier to construct an electrochemical sensing platform based on carbon ionic liquid electrode for sensitive detection of trichloroacetic acid (TCA) and potassium bromate (KBrO3), in which horseradish peroxidase (HRP) was used as the catalyst and Au nanoparticle was employed as signal amplifier. The detection ranges of the supposed sensing platform for testing TCA and KBrO3 were 10.0–1000.0 mM and 0.10–1.10 mM with the lower detection limits as 3.33 mM and 0.03 mM. Beside, this method was used to determine the KBrO3 content in tap water samples with satisfactory results.

Electrochemical Biosensor Based on Horseradish Peroxidase and Black Phosphorene Quantum Dot Modified Electrode.

Black phosphorene quantum dots (BPQDs) were prepared by ultrasonic-assisted liquid-phase exfoliation and centrifugation with morphologies proved by TEM results. Furthermore, an electrochemical enzyme sensor was prepared by co-modification of BPQDs with horseradish peroxidase (HRP) on the surface of a carbon ionic liquid electrode (CILE) for the first time. The direct electrochemical behavior of HRP was studied with a pair of well-shaped voltammetric peaks that appeared, indicating that the existence of BPQDs was beneficial to accelerate the electron transfer rate between HRP and the electrode surface. This was due to the excellent properties of BPQDs, such as small particle size, high interfacial reaction activity, fast conductivity, and good biocompatibility. The presence of BPQDs on the electrode surface provided a fast channel for direct electron transfer of HRP. Therefore, the constructed electrochemical HRP biosensor was firstly used to investigate the electrocatalytic behavior of trichloroacetic acid (TCA) and potassium bromate (KBrO3), and the wide linear detection ranges of TCA and KBrO3 were 4.0-600.0 mmol/L and 2.0-57.0 mmol/L, respectively. The modified electrode was applied to the actual samples detection with satisfactory results.

Fabrication of Myoglobin-Sodium Alginate-Graphene Composite Modified Carbon ionic liquid electrode via the Electrodeposition Method and Its Electrocatalysis toward Trichloroacetic Acid

Fabrication of Myoglobin-Sodium Alginate-Graphene Composite Modified Carbon ionic liquid electrode via the Electrodeposition Method and Its Electrocatalysis toward Trichloroacetic Acid

Preparation of electrochemical horseradish peroxidase biosensor with black phosphorene-zinc oxide nanocomposite and their applications.

In this work, a novel and sensitive electrochemical biosensor was constructed based on a black phosphorene (BP) and nanosized zinc oxide (ZnO@BP) nanocomposite as a modifier, which was used for the immobilization of horseradish peroxidase (HRP) on a carbon ionic liquid electrode (CILE). The ZnO@BP nanocomposite was synthesized by a simple in situ hydrothermal method with stripped black phosphorus nanoplates and ZnO. The ZnO@BP and HRP-modified electrode was developed by a casting method. ZnO@BP with highly conductivity, large surface area and good biocompatibility could maintain the bioactivity of HRP and accelerate the electron transfer rate. Cyclic voltammetry was used to study the direct electrochemistry of HRP on the Nafion/HRP/ZnO@BP/CILE with the appearance of a pair of distinct redox peaks. The constructed electrochemical HRP biosensor exhibited excellent electrocatalytic effects on the reduction of trichloroacetic acid and sodium nitrite. Real samples were detected with satisfactory results, which demonstrated the potential applications of this electrochemical HRP biosensor.

Preparation and Application of Electrochemical Horseradish Peroxidase Sensor Based on a Black Phosphorene and Single-Walled Carbon Nanotubes Nanocomposite.

To design a new electrochemical horseradish peroxidase (HRP) biosensor with excellent analytical performance, black phosphorene (BP) nanosheets and single-walled carbon nanotubes (SWCNTs) nanocomposites were used as the modifier, with a carbon ionic liquid electrode (CILE) as the substrate electrode. The SWCNTs-BP nanocomposite was synthesized by a simple in situ mixing procedure and modified on the CILE surface by the direct casting method. Then HRP was immobilized on the modified electrode with Nafion film. The electrocatalysis of this electrochemical HRP biosensor to various targets was further explored. Experimental results indicated that the direct electrochemistry of HRP was realized with a pair of symmetric and quasi-reversible redox peaks appeared, which was due to the presence of SWCNTs-BP on the surface of CILE, exhibiting synergistic effects with high electrical conductivity and good biocompatibility. Excellent electrocatalytic activity to trichloroacetic acid (TCA), sodium nitrite (NaNO2), and hydrogen peroxide (H2O2) were realized, with a wide linear range and a low detection limit. Different real samples, such as a medical facial peel solution, the soak water of pickled vegetables, and a 3% H2O2 disinfectant, were further analyzed, with satisfactory results, further proving the potential practical applications for the electrochemical biosensor.

Direct Electrochemistry of Hemin on Graphdiyne Modified Carbon Ionic Liquid Electrode and Electrocatalysis to Bromate

Direct Electrochemistry of Hemin on Graphdiyne Modified Carbon Ionic Liquid Electrode and Electrocatalysis to Bromate

Portable Wireless Intelligent Electrochemical Sensor for the Ultrasensitive Detection of Rutin Using Functionalized Black Phosphorene Nanocomposite.

To build a portable and sensitive method for monitoring the concentration of the flavonoid rutin, a new electrochemical sensing procedure was established. By using nitrogen-doped carbonized polymer dots (N-CPDs) anchoring few-layer black phosphorene (N-CPDs@FLBP) 0D-2D heterostructure and gold nanoparticles (AuNPs) as the modifiers, a carbon ionic liquid electrode and a screen-printed electrode (SPE) were used as the substrate electrodes to construct a conventional electrochemical sensor and a portable wireless intelligent electrochemical sensor, respectively. The electrochemical behavior of rutin on the fabricated electrochemical sensors was explored in detail, with the analytical performances investigated. Due to the electroactive groups of rutin, and the specific π-π stacking and cation–π interaction between the nanocomposite with rutin, the electrochemical responses of rutin were greatly enhanced on the AuNPs/N-CPDs@FLBP-modified electrodes. Under the optimal conditions, ultra-sensitive detection of rutin could be realized on AuNPs/N-CPDs@FLBP/SPE with the detection range of 1.0 nmol L−1 to 220.0 μmol L−1 and the detection limit of 0.33 nmol L−1 (S/N = 3). Finally, two kinds of sensors were applied to test the real samples with satisfactory results.

A new electrochemical sensor based on green synthesized CuO nanostructures modified carbon ionic liquid electrode for electrocatalytic oxidation and monitoring of l-cysteine

In this study, we introduced a new carbon composite electrode modified with green synthesized CuO nanostructures (CuO-NSs) for sensitive l-cysteine determination. We applied a cost-effective and green method to synthesize CuO-NSs using Terminalia catappa leaf extract as a reducer and stabilizer without other additives. The CuO nanostructures were characterized by Ultraviolet–visible spectroscopy (UV–vis), X-ray diffraction (XRD), field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FE-SEM-EDX) and elemental mapping, transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Electrochemical techniques such as cyclic voltammetry and amperometry were applied to investigate the electrochemical performance of the composite electrode for cysteine (l-Cys) electrooxidation. The composite electrode showed a noticeable shift in the electrooxidation peak potential of l-Cys over the conventional electrodes and a stable and sensitive electrochemical response by providing active sites and effective electron transfer pathways. Effects of various parameters such as pH of the solution, the amount of modifier, and scan rate were investigated on the electrochemical behavior of l-Cys. Under the optimal experimental conditions, the fabricated l-Cys sensor showed a linear relationship over an extensive concentration range of 10.0 µM to 5000.0 µM (R2 = 0.998) with a limit of detection (LOD) of 0.51 µM at physiological conditions (pH = 7.0). In addition, the composite electrode displayed high selectivity, good average reproducibility (RSD = 2.45 %), and applicability in the real sample on the l-Cys detection. The green, fast, simple, and cost-effective synthesis of CuO-NSs and good electrocatalytic activity of the modified electrode reveal good use of the prepared sensor to detect l-Cys.

Synthesis of sp-hybridized nitrogen doped ultrathin graphdiyne and application to the electrochemical detection for 6,7-dihydroxycoumarin.

As a new type of carbon nanomaterial, graphdiyne (GDY) has unique sp hybridized carbon atom, which makes it possible to develop new nitrogen-doped configurations. In this paper, sp-hybridized nitrogen atom doped ultrathin graphdiyne (NUGDY) was prepared based on graphdiyne oxide and melamine by carbonization at high temperature. NUGDY not only preserves the typical folded and wrinkled two-dimensional morphology of GDY, but also presents a three-dimensional porous network structure, which provides sufficient interface and capacity for the loading of target analyte. Meanwhile, N doping increases the GDY defects with more active sites and higher conductivity. Then, NUGDY was modified on the surface of carbon ionic liquid electrode and the modified electrode was applied to 6,7-dihydroxycoumarin (6,7-DHC) analysis. Cyclic voltammetry, electrochemical impedance spectroscopy and chronocoulometry results show that NUGDY has good promotive effect to the electrode performances. Differential pulse voltammetric experiments show that this electrochemical sensor has a low detection limit as 2.3nM (3S0/S) for 6,7-DHC with high sensitivity. In addition, the modified electrode has the characteristics of excellent anti-interference ability and stability, and been successfully used in the real samples determination, which provides a promising method for the sensitive detection of drug molecules.

Porous biomass carbon and gold nanoparticles modified electrode for myoglobin direct electrochemistry and electrocatalysis

AbstractIn this paper, a stable porous biomass carbon (BC) and gold (Au) nanoparticles modified carbon ionic liquid electrode (CILE) was prepared for the investigation of direct electrochemistry and electrocatalysis of myoglobin (Mb). BC was synthesized via pyrolysis of Hainan's natural tropical plant Lagerstroemia indica leaves, which was modified on the surface of CILE with Au nanoparticles further electrodeposited on the electrode surface. Then, Mb was cast on the nanocomposite‐modified electrode to obtain an electrochemical sensing platform with Nafion film (Nafion/Mb/Au−BC/CILE). Direct electrochemistry of Mb on the modified electrode was investigated with appearance of a pair of enhanced redox peaks, indicating direct electron transfer rate of Mb was accelerated due to the presence of Au−BC nanocomposite. Au−BC nanocomposite exhibited high conductivity, good biocompatibility, and large surface area, which was beneficial for electron transfer of Mb. The Mb modified electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) and sodium nitrite (NaNO2), which was further used to establish a new electroanalytical method with satisfied sensitivity in real samples analysis.

Nanomolar determination of Penicillin G potassium (PGK) salt using a Carbon Paste Electrode modified with TiO2 nano particles /Ionic Liquids in real samples

In this work, a novel sensor based on a Carbon Ionic Liquid Electrode (CILE) and TiO2 Nano-Particles (NPs)/Ionic Liquid (IL) (octylpyridinium iodide) was introduced. We demonstrated the electrochemical behavior and applications of a Carbon Paste Electrode (CPE) modified with TiO2 NPs/IL (TiO2 NPs/CILE) for the determination of penicillin G potassium (PGK) at a pH value of 7.0 through Cyclic Voltammetry (CV) and Square-Wave Voltammetry (SWV) techniques. Characterization of this new sensor was performed by using different techniques, including Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). All the effective electrochemical parameters, such as pH, scan rate, step increment, frequency, and pulse amplitude, on PGK detection were studied. PGK showed a linear square-wave voltammetric response within the dynamic range of 3.0–1000.0 nM associated with the regression factor (R2) of 0.9940, Limit of Detection (LOD) of 2.09 nM, and Limit of Quantification (LOQ) of 6.95 nM. The practical applicability of TiO2 NPs/ILCE was examined by evaluating PGK detection in milk, pharmaceutical formulations, and biological samples, which resulted in satisfied recoveries.

A novel self-assembled gold nanoparticles-molecularly imprinted modified carbon ionic liquid electrode with high sensitivity and selectivity for the rapid determination of bisphenol A leached from plastic containers

In the present work, a new nanocomposite, reduced graphene oxide (rGO) decorated by mercaptamine- gold nanoparticles (AuNPs-MCA-rGO) was synthesized for the first time by a facile hydrothermal method. The carbon ionic liquid electrode (CILE) was modified by AuNPs-MCA-rGO and molecular imprinted polymer (MIP) to sensitive and selective electrochemical microanalysis of bisphenol A (BPA). The modifier provides a large surface area, selective sites and exhibited a rapid electron transport rate for the bisphenol A (BPA). In this research, a new electrochemical microcell with a volume of 25 µL was fabricated which can reduce drastically the required volume of analysis. This advantage leads to less use of chemicals and the possibility of micro sample analyzing. Therefore, the method is presented as a economical electro-analytical method. Under the optimized conditions, the linear response was observed for BPA concentration in the range of 4.0 × 10−9 to 1.8 × 10−5 M by cyclic voltammetry (CV). The detection limit of the method was obtained as 1.1 × 10−9 M by CV. Because of imprinted polymers in composition of modifier, the proposed sensor shows great potential applications in biomarker detection, food safety testing and environmental monitoring. It was used for the quantitative determination of BPA leached from plastic containers for food storage (PVC food package, PC baby bottle, and PC water bottle).

Development of an Electrochemical DNA Biosensor Based on Gold Nanoparticles and Thiol Graphene Nanocomposite for Detection of a Specific nuc Gene from Staphylococcus aureus

Background:: An electrochemical DNA biosensor based on gold nanoparticles (AuNPs) and thiol graphene (TGR) nanocomposite modified carbon ionic liquid electrode (CILE) was developed to detect a specific nuc gene of Staphylococcus aureus, which was further used in the analysis of PCR amplification samples from unfrozen pork. Objective:: The development of a DNA biosensor derived from AuNPs-coated TGR could be used as a novel sensing method for the detection of specific ssDNA sequences in biological and clinical samples. Methods: The electrochemical properties of modified CILE electrodes were determined by cyclic voltammetry and electrochemical impedance spectroscopy, and the electrochemical performances of the biosensor were investigated by differential pulse voltammetry. Results:: This gene sensor was able to detect the specific nuc gene from Staphylococcus aureus over the concentration range from 1.0×10-15 mol L-1 to 1.0×10-6 mol L-1 with a limit of detection of 4.5×10-16 mol L-1 (3σ), and it was applied in the detection of Staphylococcus aureus in an unfrozen pork sample after PCR amplification of the nuc gene with satisfactory results. Conclusion:: This gene biosensor showed high sensitivity and good selectivity, wide detection range and low detection limit, which demonstrated an effective tool to detect specific nuc gene sequences of Staphylococcus aureus.

Application of Graphdiyne and Gold Nanoparticles Nanocomposite Modified Electrode for the Detection of 7-Hydroxy-6-Methoxy-Hydrocoumarin, A Natural Compound

In this paper, a graphdiyne (GDY) and gold nanoparticles (AuNPs) nanocomposite was formed with AuNPs growing on the surface and between the layers of GDY, which was used as the sensing interface on carbon ionic liquid electrode (CILE) to detect 7-Hydroxy-6-methoxy-hydrocoumarin (7-6-HDC) that isolated from the Noni juice of Hainan Island. The GDY-Au nanocomposite was characterized by different spectroscopic techniques, which exhibited corrugated and folded morphology with large specific surface area. The electrochemical properties of 7-6-HDC on the modified electrode were further studied with calculated based on direct electrochemical investigation and electrochemical kinetics. The GDY-Au modified electrode displayed excellent results that attributed to the highly conductive nanocomposite, where GDY structure with defects could immobilize more AuNPs to decrease the electron transfer resistance. Under the optimum conditions, GDY-Au/CILE gave a wide range of 7-6-HDC of 0.01 μM–1000.0 μM with a low detection limit (3.22 nM, 3S0/S) as well as higher sensitivity (0.97 µA/(M•cm2)).

Construction and electrochemical behavior of hemoglobin sensor based on ZnO doped carbon nanofiber modified electrode

In this paper zinc oxide (ZnO) doped carbon nanofiber (CNF) was synthesized and used for electrode modification with hemoglobin (Hb) immobilized on the surface of carbon ionic liquid electrode (CILE). Ultraviolet–visible (UV–Vis) and Fourier transform infrared spectroscopic studies showed that Hb maintained its native structure in the composite film without denaturation, indicating that the modified materials had good biocompatibility. On the modified electrode (Nafion/Hb/ZnO-CNF/CILE), direct electron transfer of Hb was achieved with well-shaped and enhanced redox waves, and electrochemical behaviors of Hb were investigated in detail. Nafion/Hb/ZnO-CNF/CILE exhibited excellent electrochemical catalytic ability to the reduction of trichloroacetic acid (TCA) and NaNO2, as indicated by a linear relationship between peak current and concentration of analytes. The biosensor was applied to the quantitative analysis of TCA in various samples with good recovery. Experimental results demonstrated the potential applications of ZnO-CNF nanocomposite as a new generation of electrochemical biosensors.

Electrochemical aptamer sensor for highly sensitive detection of mercury ion with Au/Pt@carbon nanofiber‐modified electrode

AbstractIn this paper, an electrochemical aptamer sensor was proposed for the highly sensitive detection of mercury ion (Hg2+). Carbon nanofiber (CNF) was prepared by electrospinning and high‐temperature carbonization, which was used for the loading of platinum nanoparticles (PtNPs) by the hydrothermal method. The Pt@CNF nanocomposite was modified on the surface of carbon ionic liquid electrode (CILE) to obtain Pt@CNF/CILE, which was further decorated by gold nanoparticles (AuNPs) through electrodeposition to get Au/Pt@CNF/CILE. Self‐assembling of the thiol‐based aptamer was further realized by the formation of Au‐S bond to get an electrochemical aptamer sensor (Aptamer/Au/Pt@CNF/CILE). Due to the specific binding of aptamer probe to Hg2+ with the formation of T‐Hg2+‐T structure, a highly sensitive quantitative detection of Hg2+ could be achieved by recording the changes of current signal after reacting with Hg2+ within the concentration range from 1.0 × 10−15 mol/L to 1.0 × 10−6 mol/L and the detection limit of 3.33 × 10−16 mol/L (3σ). Real water samples were successfully analyzed by this method.

Au-Pt@Biomass porous carbon composite modified electrode for sensitive electrochemical detection of baicalein

A gold and platinum bimetal decorated biomass porous carbon (Au-Pt@BPC) composite was synthesized by carbonization of oyster mushroom and solvothermal method, which was applied to the electrode modification and electrochemical detection of baicalein. The structural and elemental aspects of Au-Pt@BPC were analyzed by X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and Raman spectrum. The Au-Pt@BPC modified carbon ionic liquid electrode (CILE) was prepared as working electrode for the detection of baicalein. Baicalein exhibited a pair of redox peak on cyclic voltammograms with enhanced peak currents, which proved the positive effects of the composite including the high conductivity of bimetal, the catalytic activity of noble metal and the large-surface of porous carbon with excellent adsorption ability. Under the optimal conditions the oxidation peak currents of baicalein were linear with the concentration in 0.48–2.0 μmol L−1 and 4.0–140.0 μmol L−1via differential pulse voltammetry and the limit of detection was calculated as 0.010 μmol L−1. The modified electrode was successfully applied to the detection of baicalein content in drug and human urine samples. Meanwhile, the low cost and facile preparation of oyster mushroom based BPC made it become a potential substrate material for electrode modification.