A novel non-enzyme hydrogen peroxide sensor based on an electrode modified with carbon nanotube-wired CuO nanoflowers

We have prepared a novel sensor for hydrogen peroxide that is based on a glassy carbon electrode modified with a film containing multi-walled carbon nanotubes wired to CuO nanoflowers. The nanoflowers were characterized by X-ray powder diffraction, and the electrode was characterized by cyclic voltammetry (CV) and scanning electron microscopy. The response of the modified electrode towards hydrogen peroxide was investigated by CV and chronoamperometry and showed it to exhibit high electrocatalytic activity, with a linear range from 0.5?μM to 82?μM and a detection limit of 0.16?μM. The sensor also displays excellent selectivity and stability.

Direct Electrochemistry of Hemoglobin Immobilized on Carbon‐Coated Iron Nanoparticles for Amperometric Detection of Hydrogen Peroxide

A novel method for preparation of hydrogen peroxide biosensor was presented based on immobilization of hemoglobin (Hb) on carbon‐coated iron nanoparticles (CIN). CIN was firstly dispersed in a chitosan solution and cast onto a glassy carbon electrode to form a CIN/chitosan composite film modified electrode. Hb was then immobilized onto the composite film with the cross‐linking of glutaraldehyde. The immobilized Hb displayed a pair of stable and quasireversible redox peaks and excellent electrocatalytic reduction of hydrogen peroxide (H₂O₂), which leading to an unmediated biosensor for H₂O₂. The electrocatalytic response exhibited a linear dependence on H₂O₂ concentration in a wide range from 3.1 μM to 4.0 mM with a detection limit of 1.2 μM (S/N=3). The designed biosensor exhibited acceptable stability, long‐term life and good reproducibility.     

Graphene–Pt nanocomposite for nonenzymatic detection of hydrogen peroxide with enhanced sensitivity

A sensitive hydrogen peroxide (H₂O₂) sensor was fabricated based on graphene–Pt (GN–Pt) nanocomposite. The GN–Pt was synthesized by photochemical reduction of K₂PtCl₄ on GNs, and characterized by atomic force microscope (AFM), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy (EDS). Electrochemical investigations indicated that the GN–Pt exhibited a high peak current and low overpotential towards the reduction of H₂O₂. The GN–Pt modified glass carbon electrode displayed a wide linear range (2–710 μM), low limit of detection (0.5 μM) and good selectivity for detection of H₂O₂ with a much higher sensitivity than that of Pt nanoparticles or graphene modified electrode.     

Synthesis of Ferrocene Based Naphthoquinones and its Application as Novel Non‐enzymatic Hydrogen Peroxide

At present, a highly sensitive hydrogen peroxide (H₂O₂) sensor is fabricated by ferrocene based naphthaquinone derivatives as 2,3‐Diferrocenyl‐1,4‐naphthoquinone and 2‐bromo‐3‐ferrocenyl‐1,4‐naphthoquinone. These ferrocene based naphthaquinone derivatives are characterized by H‐NMR and C‐NMR. The electrochemical properties of these ferrocene based naphthaquinone are investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) on modified glassy carbon electrode (GCE). The modified electrode with ferrocene based naphthaquinone derivatives exhibits an improved voltammetric response to the H₂O₂ redox reaction. 2‐bromo‐3‐ferrocenyl‐1,4‐naphthoquinone show excellent non‐enzymatic sensing ability towards H₂O₂ response with a detection limitation of 2.7 μmol/L a wide detection range from 10 μM to 400 μM in H₂O₂ detection. The sensor also exhibits short response time (1 s) and good sensitivity of 71.4 μA mM^?1 cm^?2 and stability. Furthermore, the DPV method exhibited very high sensitivity (18999 μA mM^?1 cm^?2) and low detection limit (0.66 μM) compared to the CA method. Ferrocene based naphthaquinone derivative based sensors have a lower cost and high stability. Thus, this novel non‐enzyme sensor has potential application in H₂O₂ detection.     

A Third‐Generation Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Covalently Immobilized on Electrografted Organic Film on Screen‐Printed Carbon Electrode

A new convenient strategy to fabricate a third‐generation hydrogen peroxide biosensor was described. The screen‐printed carbon electrode (SPCE) was first modified with a layer of 4‐nitrophenyl assembled from the 4‐nitroaniline diazonium salt synthesized in situ in acidic aqueous solution. Next, the nitro groups were converted to amines followed by crosslinking to the horseradish peroxidase (HRP) by glutaraldehyde. The redox chemistry of the active center of the HRP was observed and the HRP‐modified electrode displayed electrocatalytic activity towards the reduction of hydrogen peroxide (H₂O₂) without any mediators. H₂O₂ was determined in a linear range from 5.0 μM to 50.0 μM, with a detection limit of 1.0 μM. Furthermore, the biosensor exhibited fast amperometric response, good reproducibility and long‐term stability.     

Self‐Assembled Prussian Blue Nanoparticles Based Electrochemical Sensor for High Sensitive Determination of H2O2 in Acidic Media

In this paper, self‐assembled Prussian blue nanoparticles (PBNPs) on carbon ceramic electrode (CCE) were developed as a high sensitive hydrogen peroxide (H₂O₂) electrochemical sensor. The PBNPs film was prepared by a simple dipping method. The morphology of the PBNPs‐modified CCE was characterized by scanning electron microscopy (SEM). The self‐assembled PB film exhibited sufficient mechanical, electrochemical stability and high sensitivity in compare with other PB based H₂O₂ sensors. The sensor showed a good linear response for H₂O₂ over the concentration range 1 μM–0.26 mM with a detection limit of ca. 0.7 μM (S/N=3), and sensitivity of 754.6 mA M^?1 cm^?2. This work demonstrates the feasibility of self‐assembled PBNPs‐modified CCE for practical sensing applications.     

Electrocatalytic Reduction of H2O2 and Oxygen on the Surface of Thionin Incorporated onto MWCNTs Modified Glassy Carbon Electrode: Application to Glucose Detection

A new H₂O₂ enzymeless sensor has been fabricated by incorporation of thionin onto multiwall carbon nanotubes (MWCNTs) modified glassy carbon electrode. First 50 μL of acetone solution containing dispersed MWCNTs was pipetted onto the surface of GC electrode, then, after solvent evaporations, the MWCNTs modified GC electrode was immersed into an aqueous solution of thionin (electroless deposition) for a short period of time <5–50 s. The adsorbed thin film of thionin was found to facilitate the reduction of hydrogen peroxide in the absence of peroxidase enzyme. Also the modified electrode shows excellent catalytic activity for oxygen reduction at reduced overpotential. The rotating modified electrode shows excellent analytical performance for amperometric determination of hydrogen peroxide, at reduced overpotentials. Typical calibration at ?0.3 V vs. reference electrode, Ag/AgCl/3 M KCl, shows a detection limit of 0.38 μM, a sensitivity of 11.5 nA/μM and a liner range from 20 μM to 3.0 mM of hydrogen peroxide. The glucose biosensor was fabricated by covering a thin film of sol–gel composite containing glucose oxides on the surface of thionin/MWCNTs modified GC electrode. The biosensor can be used successfully for selective detection of glucose based on the decreasing of cathodic peak current of oxygen. The detection limit, sensitivity and liner calibration rang were 1 μM, 18.3 μA/mM and 10 μM–6.0 mM, respectively. In addition biosensor can reach 90% of steady currents in about 3.0 s and interference effect of the electroactive existing species (ascorbic acid–uric acid and acetaminophen) is eliminated. The usefulness of biosensor for direct glucose quantification in human blood serum matrix is also discussed. This sensor can be used as an amperometric detector for monitoring oxidase based biosensors.     

Non-enzymatic hydrogen peroxide sensor based on a nanoporous gold electrode modified with platinum nanoparticles

A novel non-enzymatic electrochemical sensor based on a nanoporous gold electrode modified with platinum nanoparticles was constructed for the determination of hydrogen peroxide (H₂O₂). Platinum nanoparticles exhibit good electrocatalytic activity towards hydrogen peroxide. The nanoporous gold (NPG) increases the effective surface area and has the capacity to promote electron-transfer reactions. With electrodeposition of Pt nanoparticles (NPs) on the surface of the nanoporous gold, the modified Au electrode afforded a fast, sensitive and selective electrochemical method for the determination of H₂O₂. The linear range for the detection of H₂O₂ was from 1.0 × 10^?7 M to 2.0 × 10^?5 M while the calculated limit of detection was 7.2 × 10^?8 M on the basis of the 3σ/slope (σ represents the standard deviation of the blank samples). These findings could lead to the widespread use of electrochemical sensors to detect H₂O₂.     

A Non‐Enzymatic Hydrogen Peroxide Sensor Based on Ag/MnOOH Nanocomposites

A novel non‐enzymatic sensor based on Ag/MnOOH nanocomposites was developed for the detection of hydrogen peroxide (H₂O₂). The H₂O₂ sensor was fabricated by immobilizing Ag/MnOOH nanocomposites on a glassy carbon electrode (GCE). The morphology and composition of the sensor surface were characterized using scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, transmission electron microscopy and X‐ray diffraction spectroscopy. The electrochemical investigation of the sensor indicates that it possesses an excellent electrocatalytic property for H₂O₂, and could detect H₂O₂ in a linear range from 5.0 µM to 12.8 mM with a detection limit of 1.5 µM at a signal‐to‐noise ratio of 3, a response time of 2 s and a sensitivity of 32.57 µA mM^?1 cm^?2. Additionally, the sensor exhibits good anti‐interference. The good analytical performance, low cost and straightforward preparation method made this novel electrode material promising for the development of effective non‐enzymatic H₂O₂ sensor.     

A novel hydrogen peroxide sensor based on Ag nanoparticles electrodeposited on DNA-networks modified glassy carbon electrode

A novel strategy to fabricate hydrogen peroxide (H₂O₂) sensor was developed by electrodepositing Ag nanoparticles (NPs) on a glassy carbon electrode modified with three-dimensional DNA networks. The result of electrochemical experiments showed that such constructed sensor had a favorable catalytic ability to reduction of H₂O₂. The well catalytic activity of the sensor was ascribed to the DNA networks that facilitated the formation and homogenous distribution of small Ag NPs. The resulted sensor achieved 95% of the steady-state current within 2 s and had a 1.7 μM detection limit of H₂O₂.     

Amperometric biosensor for hydrogen peroxide based on the co-electrodeposition of horseradish peroxidase and methylene blue on an ITO electrode modified with an anodic aluminum oxide template

We report on a nano-array sensor for hydrogen peroxide (H₂O₂) that is based on a nanoporous anodic aluminum oxide template. This was used as a matrix for the co-immobilization of horseradish peroxidase (HRP) and methylene blue (MB) on the surface of an indium tin oxide electrode. The immobilized HRP retained its natural activity and MB is capable of efficiently shuttle electrons between HRP and the electrode. The new electrode was characterized by SEM and electrochemical methods. It exhibits fast response, long-term stability, high sensitivity and good selectivity to H₂O₂. Under optimized conditions, it linearly responds to H₂O₂ in the concentration range from 1.0?μM to 26?mM, with a detection limit of 0.21?μM (at S/N?=?3).

Mediatorless Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Immobilized on 4‐Carboxyphenyl Film Electrografted on Gold Electrode

A novel method to fabricate a third‐generation hydrogen peroxide biosensor was reported. The electrode was first derivatized by electrochemical reduction of in situ generated 4‐carboxyphenyl diazonium salt (4‐CPDS) in acidic aqueous solution yielded stable 4‐carboxyphenyl (4‐CP) layer. The horseradish peroxidase (HRP) enzyme was then covalently immobilized by amidation between NH₂ terminus of enzyme and COOH terminus of 4‐CP film making use of the carbodiimide chemistry. Electrodeposition conditions used to control electrode functionalization density and film electron transfer kinetics were assessed by chronoamperometry and electrochemical impedance spectroscopy. The immobilized HRP displayed excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H₂O₂) without any mediators. The effect of various operational parameters was explored for optimum analytical performance. The reported biosensor exhibited fast amperometric response (within 5 s) to H₂O₂. The detection limit of the biosensor was 5 μM, and linear range was from 20 μM to 20 mM. Furthermore, the biosensor exhibited high sensitivity, good reproducibility, and long‐term stability.     

An amperometric biosensor based on the coimmobilization of horseradish peroxidase and methylene blue on a β-type zeolite modified electrode

A new biosensor for the amperometric detection of hydrogen peroxide was developed based on the co-immobilization of horseradish peroxidase (HRP) and methylene blue on a β-type zeolite modified glassy carbon electrode without the commonly used bovine serum albumin-glutaraldehyde. The intermolecular interaction between enzyme and zeolite matrix was investigated using FT-IR. The cyclic voltammetry and amperometric measurement demonstrated that methylene blue co-immobilized with HRP in this way displayed good stability and could efficiently transfer electrons between immobilized HRP and the electrode. The sensor responded rapidly to H₂O₂ in the linear range from 2.5 × 10^–6 to 4.0 × 10^–3 M with a detection limit of 0.3 μM. The sensor was stable in continuous operation.     

Low‐Potential Sensitive Hydrogen Peroxide Detection Based on Nanotubular TiO2 and Platinum Composite Electrode

In this work, a novel sensor for detecting hydrogen peroxide was constructed on the base of nanotubular TiO₂ and platinum nanoparticles. The morphology, structural, and electrochemical properties of the Pt/TiO₂ nanocomposite electrodes were characterized by SEM, XRD and electrochemical methods. With an operating potential of +0.3 V versus Ag/AgCl, the sensor produces catalytic oxidation currents at the nanocomposite electrode, which can be exploited for quantitative determinations. The amperometric signals are linearly proportional to hydrogen peroxide concentration in the range 4×10^?6 to 1.25×10^?3 M. The regression equation is I (μA)=0.85 c (mM)+0.16 with a correction coefficient of 0.997. At a signal‐to‐noise ratio of 3, a detection limit of 4.0 μM H₂O₂ can be observed for the nanocomposite electrode. In addition, the sensor has a good stability and reproducibility. The construction process is simple and inexpensive. The results demonstrated that nanotubular TiO₂ exhibits great prospect for developing a class of ideal and novel bioreactors and biosensors.     

Non-enzymatic hydrogen peroxide sensor based on a gold electrode modified with granular cuprous oxide nanowires

Granular nanowires with a diameter of about 60 nm were fabricated from cuprous oxide (Cu₂O) by an electrochemical method using anodic aluminium oxide as the template. A non-enzymatic sensor for hydrogen peroxide (H₂O₂) was then developed on the basis of a gold electrode modified with Cu₂O nanowires and Nafion. The resulting sensor enables the determination of H₂O₂ with a sensitivity of 745 μA?mM^?1?cm^?2, over a wide linear range (0.25 μM to 5.0 mM), and with a low detection limit (0.12 μM). The results demonstrate that the use of such granular nanowires provides a promising tool for the design of non-enzymatic chemical sensors.

An Amperometric Biosensor Based on the Coimmobilization of Horseradish Peroxidase and Methylene Blue on a Carbon Nanotubes Modified Electrode

A novel hydrogen peroxide biosensor has been constructed based on the characteristics of the carbon nanotube. The multiwall carbon nanotube (MWNT) was used as a coimmobilization matrix to incorporate horseradish peroxidase (HRP) and electron transfer mediator methylene blue (MB) onto a glassy carbon electrode surface. Cyclic voltammetry and amperometric measurements were employed to demonstrate the feasibility of methylene blue as an electron carrier between the immobilized peroxidase and the surface of glassy carbon electrode. The amperometric response of this resulting biosensor to H₂O₂ shows a linear relation in the range from 4 μM to 2 mM. The detection limit was 1 μM when the signal to noise ratio is 3. The presence of dopamine and ascorbic acid hardly affects the sensitive determination of H₂O₂. This biosensor also possesses very good stability and reproducibility.     

Sensitive Amperometric Sensing of Hydrogen Peroxide Using Ag Nanowire Array Electrode

The amperometric sensor based on a silver nanowire (80 nm in diameter Ag NW) array electrode was fabricated and characterized with scanning electron microscope (SEM). The electrode showed good electrocatalytic activity for reduction of hydrogen peroxide. The effects of the applied polarization potential, pH, time interval between successive injections of analyte, injection volume and H₂O₂ concentration in a single injection on the electrochemical performance of the sensor were studied. It was found that the optimized operating conditions for the proposed sensor are: the potential of ?200 mV, pH between 7.4 and 9.0, 60 s time interval, 10 µL injection volume, and 500 µM H₂O₂ in single injection. The proposed Ag NW array sensor is free of interference from ascorbic acid, uric acid and glucose.     

Highly Selective Nanostructured Electrochemical Sensor Utilizing Densely Packed Ultrathin Gold Nanowires Film

The number of studies conducted about nonenzymatic electrochemical sensors has increased in recent years due to the development of more stable and robust electrodes using noble metals. One of the key aspects for achieving high sensing performance including detection limit and sensitivity is the design of electrode architecture. Herein, we report a new electrochemical sensing platform featuring ultrathin standing gold nanowires (AuNWs) for nonenzymatic detection of hydrogen peroxide (H₂O₂). The use of AuNWs resulted in an increased electron transfer efficiency due to the higher active surface area compared to traditional gold film electrodes. This sensor demonstrates good selectivity, reproducibility, a linear range up to 49.5 mM of H₂O₂ with a sensitivity of 0.185±0.003 mAmM^?1cm^?2 and a limit of detection of 111 μM. The biological relevance of this sensor was tested in cell culture media to illustrate the performance of the proposed sensing electrode in complex biological media.     

Flow Injection Determination of Hydrogen Peroxide Using a Carbon Paste Electrode Modified with a Manganese Dioxide Film

Abstract

A manganese dioxide film modified carbon paste electrode was developed for use as an amperometric sensor for the determination of hydrogen peroxide (H₂O₂) in ammoniacal aqueous solutions. The electrode showed a stable response towards H₂O₂ after electrochemical activation. Effects of flow rate, operating potential, concentration, injection volume and interferences were investigated. A linear response towards H₂O₂ from 5 μg.l^?1 to 450 mg.l^?1 and a detection limit (3 signal-to-noise ratio) of 4.7 μg.l^?1 was found. The method was employed for the determination of H₂O₂ in rain water samples.     

Simultaneous Determination of Peroxide Hydrogen and Ascorbic Acid by Capillary Electrophoresis with Platinum Nanoparticles Modified Micro‐disk Electrode

In this study, the first application of a capillary zone electrophoresis‐electrochemical detection (CE‐ECD) method for concurrent determination of hydrogen peroxide (H₂O₂) and ascorbic acid (AA), was developed using the Pt nanoparticles (PtNPs) modified Pt micro‐disk electrode (PtME). The electrocatalytic activity of the modified electrode for H₂O₂ and AA was characterized by cyclic voltammetry. Under optimized experimental conditions, highly linear calibration plots were observed for both H₂O₂ and AA, with concentration linear ranges of 0.8 μM to 0.8 mM and 1.0 μM to 0.8 mM. Detection limits of 0.2 μM H₂O₂ and 0.5 μM AA were determined on the basis of the signal‐to‐noise characteristics (S/N=3) of an electropherogram. Compared with the unmodified PtME, the sensitivity was promoted in that PtNPs/PtME provided an increased effective electrode surface and high catalytic activity toward H₂O₂ and AA. Using this method, the added H₂O₂ and AA in Mizone, a kind of functional drink, were detected, and the concentration of AA was found to be 2.33 mM (n =3). The recovery rates were 95.3 % for H₂O₂ and 98.7 % for AA. The novel approach provided a wide linear range, low detection limit, good reproducibility and stability. It will provide a new insight into the balance of reactive oxygen species and antioxidant in biological systems.