Preparation of cadmium sulfide nanoparticles and their application for improving the properties of the electrochemical sensor for the determination of enrofloxacin in real samples

An advanced electrochemical sensor for the detection of enrofloxacin (ENR) based on the use of a modified electrode containing cadmium sulfide (CdS) nanoparticles (NPs) is reported. The CdS NPs were synthesized and characterized and then coated onto the electrode to fabricate a modified electrode that exhibited a lower limit of detection of 9.5 × 10^?8 mol·L^?1. This detection limit compares with a traditional electrode that exhibited a concentration detection range of 1.0 × 10^?2 to 1.0 × 10^?7 mol·L^?1. This modified electrode demonstrated good selectivity, reproducibility, response time (<40 s), lifetime (up to 12 wk), and pH range (3.3‐7.2) for the determination of ENR in real samples (eg, pig urine).     

A new biosensor for glucose determination in serum based on up-converting fluorescence resonance energy transfer

In this work, a new glucose sensor based on up-converting fluorescence resonance energy transfer (UC-FRET) was developed. Up-converting phosphors (UCPs, NaYF(4): Yb, Er), which were covalently labeled with Concanavalin A (ConA), were used as the energy donor with thiolated β-cyclodextrins (SH-β-CDs) functionalized gold nanoparticles as the energy acceptor. Due to the combination between ConA and SH-β-CDs, the energy donor and the acceptor were brought to close proximity, resulting in the quenching of the fluorescence of UCPs by gold nanoparticles. In the presence of glucose which competed with SH-β-CDs towards the binding sites of ConA, the biosensor (UCPs-ConA-SH-β-CDs-Au) was decomposed and the energy donor was separated from the acceptor. Therefore, the fluorescence of UCPs was restored dependent on the concentration of glucose. The increase of UCPs fluorescence intensity was proportional to glucose concentration within the range from 0.4 μM to 10μM in aqueous buffer, with a limit of detection (LOD) of 0.043 μM. A same linear range of glucose concentration was obtained in a human serum matrix (which was pretreated and thus contained no glucose) with a slightly higher LOD (0.065 μM). The glucose sensor was applied to real human serum samples with the results consistent with that of a classic hexokinase (HK) method, indicating that the UC-FRET biosensor was competent for directly sensing glucose in serum samples without optical interference, which benefited from the near infrared (NIR) excitation nature of UCPs. The results of this work suggested that the UC-FRET technique could be a promising alternative for detecting biomolecules in complex biological sample matrixes for diagnostic purposes.     

Electrochemical immunoanalysis of cardiac myoglobin

Methods of myoglobin determination based on electrochemical analysis by means of analysis of electrochemical parameters of modified electrodes have been proposed. The method of direct detection is based on interaction of myoglobin with anti-myoglobin with subsequent electrochemical registration of this hemoprotein. The electrode surface was modified by a membrane-like synthetic didodecyldimethylammonium bromide (DDAB), gold nanoparticles and antibodies to human cardiac myoglobin the electrochemical reduction of myoglobin heme was registered provided that the antigen (myoglobin) was present in the samples. The reaction of myoglobin binding to antibodies immobilized on the electrode surface was also registered using electrochemical impedance spectroscopy. The study of electro analytical characteristics revealed high specificity and sensitivity of the developed method. The biosensor was characterized by low detection limit and a high working range of the detected concentrations from 17.8 to 1780 ng/ml (from 1 to 100 nM). The method of myoglobin determination based on a signal of gold nanoparticles has also been proposed. The signal was detected with stripping voltammetry. There was a change in the cathodic peak area and the peak height of gold oxide reduction for the electrodes with antibodies and the electrodes with the antibody-myoglobin complex.     

A novel electroconductive interface based on Fe3O4 magnetic nanoparticle and cysteamine functionalized AuNPs: Preparation and application as signal amplification element to minoring of antigen‐antibody immunocomplex and biosensing of prostate cancer

In this study, a novel electroconductive interface was prepared based on Fe₃O₄ magnetic nanoparticle and cysteamine functionalized gold nanoparticle. The engineered interface was used as signal amplification substrate in the electrochemical analysis of antibody‐antigen binding. For this purpose, biotinilated‐anti‐prostate‐specific antigen (PSA) antibody was bioconjugated with iron oxide magnetic nanoparticles (Fe₃O₄) and drop‐casted on the surface of glassy carbon electrode (GCE). Also, secondary antibody (HRP‐Ab2) encapsulated on gold nanoparticles caped by cysteamine was immobilized on the surface of GCE modified electrode. A transmission electron microscopy images shows that a sandwich immunoreaction was done and binding of Ab1 and Ab2 performed successfully. Various parameters of immunoassay, including the loading of magnetic nanoparticles, the amount of gold nanoparticle conjugate, and the immunoreaction time, were optimized. The detection limit of 0.001 μg. L^?1 of PSA was obtained under optimum experimental conditions. It is found that such magneto‐bioassay could be readily used for simultaneous parallel detection of multiple proteins by using multiple inorganic metal nanoparticle tracers and are expected to open new opportunities for early stage diagnosis of cancer in near future.     

Highly sensitive sensor for picomolar detection of insulin at physiological pH, using GC electrode modified with guanine and electrodeposited nickel oxide nanoparticles

The electrochemical behavior of insulin at glassy carbon (GC) electrode modified with nickel oxide nanoparticles and guanine was investigated. Cyclic voltammetry technique has been used for electrodeposition of nickel oxide nanoparticles (NiOx) and immobilization of guanine on the surface GC electrode. In comparison to glassy carbon electrode modified with nickel oxide nanoparticles and bare GC electrode modified with adsorbed guanine, the guanine/nickel oxide nanoparticles/modified GC electrode exhibited excellent catalytic activity for the oxidation of insulin in physiological pH solutions at reduced overpotential. The modified electrode was applied for insulin detection using cyclic voltammetry or hydrodynamic amperometry techniques. It was found that the calibration curve was linear up to 4muM with a detection limit of 22pM and sensitivity of 100.9pA/pM under the optimized condition for hydrodynamic amperometry using a rotating disk modified electrode. In comparison to other electrochemical insulin sensors, this sensor shows many advantages such as simple preparation method without using any special electron transfer mediator or specific reagent, high sensitivity, excellent catalytic activity at physiological pH values, short response time, long-term stability and remarkable antifouling property toward insulin and its oxidation product. Additionally, it is promising for the monitoring of insulin in chromatographic effluents.     

Electrochemical immunosensor for the milk allergen β-lactoglobulin based on electrografting of organic film on graphene modified screen-printed carbon electrodes

A novel label-free voltammetric immunosensor for sensitive detection of β-lactoglobulin using graphene modified screen printed electrodes has been developed. The derivatization of the graphene electrode surface was achieved by electrochemical reduction of in situ generated 4-nitrophenyl diazonium cations in aqueous acidic solution, followed by electrochemical reduction of the terminal nitro groups to amines. The electrochemical modification protocol was optimized in order to generate monolayer of nitrophenyl groups on the graphene surface without complete passivation of the electrode. Unlike the reported method for graphene functionalization, we demonstrated here the ability of the electrografting of aryl diazonium salt to attach an organic film to the graphene surface in a controlled manner by choosing the suitable grafting protocol. Next, the amine groups on the graphene surface were activated using glutaraldehyde and used for the covalent immobilization of β-lactoglobulin antibodies. Cyclic and differential pulse voltammetry carried out in an aqueous solution containing [Fe(CN)(6)](3-/4-) redox pair have been used for the immunosensor characterization. The results demonstrated that the DPV reduction peak current of [Fe(CN)(6)](3-/4-) decreased linearly with increasing the concentration of β-lactoglobulin due to the formation of antibody-antigen complex on the modified electrode surface. The immunosensor obtained using this novel approach enabled a detection limit of 0.85pgmL(-1) and a dynamic range from 1pgmL(-1) to 100ngmL(-1) of β-lactoglobulin in PBS buffer. In addition, the immunosensor evaluated in different samples including cake, cheese snacks, a sweet biscuit, showing excellent correlation with the results obtained from commercially enzyme-linked immunosorbent assay (ELISA) method.     

A highly sensitive nanostructure-based electrochemical sensor for electrocatalytic determination of norepinephrine in the presence of acetaminophen and tryptophan

A new electrochemical sensor for the determination of norepinephrine (NE), acetaminophen (AC) and tryptophan (Trp) is described. The sensor is based on carbon paste electrode (CPE) modified with 3,4-dihydroxybenzaldehyde-2,4-dinitrophenylhydrazone (DDP) and takes the advantages of carbon nanotubes (CNTs), which makes the modified electrode highly sensitive for the electrochemical detection of these compounds. Cyclic voltammetry (CV) at various scan rates was used to investigate the redox properties of the modified electrode. The apparent charge transfer rate constant, k(s), and transfer coefficient, α, for electron transfer between DDP and CNT paste electrode were calculated. The mediated oxidation of NE at the modified electrode was investigated by CV and the values of k, α and diffusion coefficient (D) were calculated. Under the optimum pH of 7.0, the oxidation of NE occurs at a potential about 215 mV less positive than that of the unmodified CPE. Differential pulse voltammetry (DPV) of NE at the modified electrode exhibited two linear dynamic ranges with a detection limit (3σ) of 77±2 nM. DPV was used for simultaneous determination of NE, AC and Trp at the modified electrode, and quantitation of NE in some real samples by the standard addition method.     

Celiac disease detection using a transglutaminase electrochemical immunosensor fabricated on nanohybrid screen-printed carbon electrodes

Celiac disease is a gluten-induced autoimmune enteropathy characterized by the presence of tissue tranglutaminase (tTG) autoantibodies. A disposable electrochemical immunosensor (EI) for the detection of IgA and IgG type anti-tTG autoantibodies in real patient's samples is presented. Screen-printed carbon electrodes (SPCE) nanostructurized with carbon nanotubes and gold nanoparticles were used as the transducer surface. This transducer exhibits the excellent characteristics of carbon-metal nanoparticle hybrid conjugation and led to the amplification of the immunological interaction. The immunosensing strategy consisted of the immobilization of tTG on the nanostructured electrode surface followed by the electrochemical detection of the autoantibodies present in the samples using an alkaline phosphatase (AP) labelled anti-human IgA or IgG antibody. The analytical signal was based on the anodic redissolution of enzymatically generated silver by cyclic voltammetry. The results obtained were corroborated with a commercial ELISA kit indicating that the electrochemical immunosensor is a trustful analytical screening tool.     

Electrochemical biosensor for the detection of cauliflower mosaic virus 35 S gene sequences using lead sulfide nanoparticles as oligonucleotide labels

Lead sulfide (PbS) nanoparticles were synthesized in aqueous solution and used as oligonucleotide labels for electrochemical detection of the 35 S promoter from cauliflower mosaic virus (CaMV) sequence. The PbS nanoparticles were modified with mercaptoacetic acid and could easily be linked with CaMV 35 S oligonucleotide probe. Target DNA sequences were covalently linked on a mercaptoacetic acid self-assembled gold electrode, and DNA hybridization of target DNA with probe DNA was completed on the electrode surface. PbS nanoparticles anchored on the hybrids were dissolved in the solution by oxidation of HNO₃ and detected using a sensitive differential pulse anodic stripping voltammetric method. The detection results can be used to monitor the hybridization reaction. The CaMV 35 S target sequence was satisfactorily detected with the detection limit as 4.38 × 10⁻¹² mol/L (3σ). The established method extends nanoparticle-labeled electrochemical DNA analysis to specific sequences from genetically modified organisms with higher sensitivity and selectivity.     

A cyclodextrin host-guest recognition approach to an electrochemical sensor for simultaneous quantification of serotonin and dopamine

An electrochemical sensor for simultaneous quantification of serotonin (5-hydroxytryptamine, 5-HT) and dopamine (DA) using a β-cyclodextrin/poly(N-acetylaniline)/carbon nanotube composite modified carbon paste electrode has been developed. Synergistic effect of multi-walled carbon nanotube (MWCNT) in addition to the pre-concentrating effect of β-cyclodextrin (β-CD) as well as its different inclusion complex stability with 5-HT and DA was used to construct an electrochemical sensor for quantification of these important neurotransmitters. The overlapping anodic peaks of 5-HT and DA at 428 mV on bare electrode resolved in two well-defined voltammetric peaks at 202 and 363 mV vs. Ag/AgCl respectively. The oxidation mechanism of 5-HT and DA on the surface of the electrode was investigated by cyclic voltammetry and it was found that the electrode processes are pH dependent and electrochemical oxidation of 5-HT is totally irreversible while the electrode gave a more reversible process to DA. Under optimized conditions, linear calibration curves were obtained in the range of about 4-200 μM with a detection limits down to sub-μM levels (S/N=3) after 20-s accumulation, for both. The proposed sensor was shown to be remarkably selective for 5-HT and DA in matrices containing different species including ascorbic acid and uric acid. The suitability of the developed method was tested for the determination of 5-HT and DA in the Randox Synthetic Plasma samples and acceptable recoveries were obtained for a set of spiked samples.     

Electrochemical immunosensor for casein based on gold nanoparticles and poly(L-Arginine)/multi-walled carbon nanotubes composite film functionalized interface

In this paper, a novel electrochemical immunosensor for the determination of casein based on gold nanoparticles and poly(L-Arginine)/multi-walled carbon nanotubes (P-L-Arg/MWCNTs) composite film was proposed. The P-L-Arg/MWCNTs composite film was used to modify glassy carbon electrode (GCE) to fabricate P-L-Arg/MWCNTs/GCE through electropolymerization of L-Arginine on MWCNTs/GCE. Gold nanoparticles were adsorbed on the modified electrode to immobilize the casein antibody and to construct the immunosensor. The stepwise assembly process of the immunosensor was characterized by cyclic voltammetry and differential pulse voltammetry. Results demonstrated that the peak currents of [Fe(CN)(6)](3-/4-) redox pair decreased due to the formation of antibody-antigen complex on the modified electrode. The optimization of the adsorption time of gold nanoparticles, the pH of supporting electrolyte and the incubation time were investigated in details. Under optimal conditions, the peak currents obtained by DPV decreased linearly with the increasing casein concentrations in the range from 1 × 10(-7) to 1 × 10(-5) g mL(-1) with a linear coefficiency of 0.993. This electrochemical immunoassay has a low detection limit of 5 × 10(-8) g mL(-1) and was successfully applied to the determination of casein in cheese samples.     

Determination of glutathione and glutathione disulfide in hepatocytes by liquid chromatography with an electrode modified with functionalized carbon nanotubes

Glutathione (GSH) and glutathione disulfide (GSSG) are important thiols, which provide defence against oxidative stress by scavenging free radicals or causing the reduction of hydrogen peroxide. The ratio GSH/GSSG is often used as a sensitive index of oxidative stress in vivo. In this paper, a direct electrochemical method using an electrode modified with functionalized carbon nanotubes as electrochemical detector (ED) for liquid chromatography (LC) was described. The electrochemical behaviors of GSH and GSSG on this modified electrode were investigated by cyclic voltammetry and it was found that the functionalized carbon nanotubes exhibited efficiently electrocatalysis on the current responses of GSH and GSSG. In LC-ED, both of the analytes showed good and stable current responses. The detection limit of GSH was 0.2 pmol on column and that of GSSG was 1.2 pmol on column, which were low enough for the analysis of real small samples. The method was sensitive enough to detect difference in concentration of GSH and GSSG in hepatocytes from animals with and without introduction of oxidation stress by glucose or hydrogenperoxide.     

Electrochemical imprinted sensor for determination of oleanic acid based on poly (sodium 4-styrenesulfonate-co-acrylic acid)-grafted multi-walled carbon nanotubes-chitosan and cobalt hexacyanoferrate nanoparticles

A novel sensitive and selective imprinted electrochemical sensor for the determination of oleanic acid was constructed on a carbon electrode by stepwise modification of functional multi-walled carbon nanotubes, cobalt hexacyanoferrate nanoparticles and a thin imprinted sol-gel film. The fabrication of a homogeneous porous poly (sodium 4-styrenesulfonate-co-acrylic acid)-grafted multi-walled carbon nanotubes/SiO(2)-chitosan nanocomposite film was conducted by controllable electrodeposition technology. The surface morphologies of the modified electrodes were characterized by scanning electron microscope. The performance of the imprinted sensor was investigated by cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy in detail. The imprinted sensor displayed high sensitivity and selectivity towards oleanic acid. A linear relationship between the sensor response signal and the logarithm of oleanic acid concentrations ranging from 1.0×10(-8) to 1.0×10(-3) mol L(-1) was obtained with a detection limit of 2.0×10(-9) mol L(-1). It was applied to the determination of oleanic acid in real capsule samples successfully.     

Electrochemical monitoring of aflatoxin M1 in milk samples using silver nanoparticles dispersed on α‐cyclodextrin‐GQDs nanocomposite

Aflatoxins are potential food pollutants produced by fungi. One of important toxins is aflatoxin M1 (AFM1). A great deal of concern is associated with AFM1 toxicity. In the present study, an innovative electrochemical interface for quantitation of AFM1 based on ternary signal amplification strategy was fabricated. In this work, silver nanoparticles was electrodeposited onto green and biocompatible nanocomposite containing α‐cyclodextrin as conductive matrix and graphene quantum dots as amplification element. Therefore, a multilayer film based on α‐cyclodextrin, graphene quantum dots, and silver nanoparticles was exploited to develop a highly sensitive electrochemical sensor for detection of AFM1. Fully electrochemical methodology was used to prepare a transducer on a glassy carbon electrode, which provided a high surface area toward sensitive detection of AFM1. The surface morphology of electrode surface was characterized by high‐resolution field emission scanning electron microscope. The proposed sensing platform provides a simple tool for AFM1 detection. Under optimized condition, the calibration curve for AFM1 concentration was linear in 0.015mM to 25mM with low limit of quantification of 2μM. The practical analytical utility of the modified electrode was illustrated by determination of AFM1 in unprocessed milk samples.     

Microfluidic immunosensor with gold nanoparticle platform for the determination of immunoglobulin G anti-Echinococcus granulosus antibodies

This article describes a microfluidic immunosensor, developed for the detection of IgG antibodies specific to Echinococcus granulosus in human serum samples, which represents an alternative tool that can be used for the immunodiagnosis of hydatidosis in an automated way. Our device consists of a Plexiglas system with a central channel and a gold electrode. For immobilization of the E. granulosus antigen, a gold electrode was modified with the incorporation of gold nanoparticles. Immobilized antigen was allowed to react with IgG-anti-E. granulosus antibodies in samples, and these were quantified by horseradish peroxidase (HRP) enzyme-labeled secondary antibodies specific to human IgG using catechol (Q) as enzymatic mediator. HRP in the presence of hydrogen peroxide (H₂O₂) catalyzes the oxidation of Q to o-benzoquinone (P). The electrochemical reduction back to Q was detected on the gold electrode (AuE) at −0.15 V. The current obtained was proportional to the activity of the enzyme and to the concentration of antibodies of interest. The detection limit for electrochemical detection was 0.091 ng ml⁻¹, and the within- and between-assay coefficients of variation were below 6.7%. The proposed system presents many benefits, the more relevant are: reduced complexity and costs that are considered as the most wanted features for the clinical-immunodiagnostic field.     

Electrochemical detection of the MT-ND6 gene and its enzymatic digestion: Application in human genomic sample

A simple electrochemical biosensor was developed for the detection of the mitochondrial NADH dehydrogenase 6 gene (MT-ND6) and its enzymatic digestion by BamHI enzyme. This biosensor was fabricated by modification of a glassy carbon electrode with gold nanoparticles (AuNPs/GCE) and a probe oligonucleotide (ssDNA/AuNPs/GCE). The probe, which is a thiolated segment of the MT-ND6 gene, was deposited by self-assembling immobilization on AuNPs/GCE. Two indicators including methylene blue (MB) and neutral red (NR) were used as the electroactive indicators and the electrochemical response of the modified electrode was measured by differential pulse voltammetry. The proposed biosensor can detect the complementary sequences of the MT-ND6 gene. Also the modified electrode was used for the detection of an enzymatic digestion process by BamHI enzyme. The electrochemical biosensor can detect the MT-ND6 gene and its enzymatic digestion in polymerase chain reaction (PCR)-amplified DNA extracted from human blood. Also the biosensor was used directly for detection of the MT-ND6 gene in all of the human genome.     

A signal-amplified electrochemical immunosensor for aflatoxin B1 determination in rice

A sensitive and simple electrochemical immunosensor based on enzymatic silver deposition amplification was constructed for the detection of aflatoxin B₁ (AFB₁) in rice. The immunosensor was based on an indirect competitive format between free AFB₁ and aflatoxin B₁-bovine serum albumin (AFB₁-BSA) conjugate immobilized on the electrode surface for binding to a fixed amount of anti-AFB₁ antibody. Then the alkaline phosphatase (ALP)-labeled anti-mouse immunoglobulin G (IgG) secondary antibody was bound to the electrode surface through reaction with primary antibody. Finally, ALP catalyzed the substrate, ascorbic acid 2-phosphate, into ascorbic acid that reduced silver ions in solution to metal silver deposited onto the electrode surface. Linear sweep voltammetry was carried out to quantify the metal silver, which indirectly reflected the amount of the analyte. The experimental parameters, such as the dilution ratio of antibody and the concentration of AFB₁-BSA conjugate, have been evaluated and optimized. At the optimal conditions, the working range of the electrochemical immunosensor was from 0.1 to 10 ng/ml with a detection limit of 0.06 ng/ml. Good recoveries were obtained for the detection of spiked rice samples. So, the proposed method in this article could find a good use for screening AFB₁ in real samples.     

Electrochemical sensor based on gold nanoparticles fabricated molecularly imprinted polymer film at chitosan-platinum nanoparticles/graphene-gold nanoparticles double nanocomposites modified electrode for detection of erythromycin

A molecularly imprinted electrochemical sensor was fabricated based on gold electrode decorated by chitosan-platinum nanoparticles (CS-PtNPs) and graphene-gold nanoparticles (GR-AuNPs) nanocomposites for convenient and sensitive determination of erythromycin. The synergistic effects of CS-PtNPs and GR-AuNPs nanocomposites improved the electrochemical response and the sensitivity of the sensor. The molecularly imprinted polymers (MIPs) were prepared by HAuCl(4), 2-mercaptonicotinic acid (MNA) and erythromycin. Erythromycin and MNA were used as template molecule and functional monomer, respectively. They were first assembled on the surface of GR-AuNPs/CS-PtNPs/gold electrode by the formation of Au-S bonds and hydrogen-bonding interactions. Then the MIPs were formed by electropolymerization of HAuCl(4), MNA and erythromycin. The sensor was characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), UV-visible (UV-vis) absorption speactra and amperometry. The linear range of the sensor was from 7.0×10(-8)mol/L-9.0×10(-5)mol/L, with the limit of detection (LOD) of 2.3×10(-8)mol/L (S/N=3). The sensor showed high selectivity, excellent stability and good reproducibility for the determination of erythromycin, and it was successfully applied to the detection of erythromycin in real spiked samples.     

A novel sensor based on electrochemical polymerization of diglycolic acid for determination of acetaminophen

Diglycolic acid (DA) polymer was coated on glassy carbon (GC) electrode by cyclic voltammetry (CV) technique for the first time. The electrochemical performances of the modified electrode were investigated by CV and electrochemical impedance (EIS). The obtained electrode showed an excellent electrocatalytic activity for the oxidation of acetaminophen (ACOP). A couple of well-defined reversible electrochemical redox peaks were observed on the ploy(DA)/GC electrode in ACOP solution. Compared with bare GC electrode, the oxidation peak potential of ACOP on ploy(DA)/GC electrode moved from 0.289 V to 0.220 V. Meanwhile, the oxidation peak current was much higher on the modified electrode than that on the bare GC electrode, indicating DA polymer modified electrode possessed excellent performance for the oxidation of ACOP. This kind of capability of the modified electrode can be enlisted for the highly sensitive and selective determination of ACOP. Under the optimized conditions, a wide linear range from 2 × 10(-8) to 5.0 × 10(-4)M with a correlation coefficient 0.9995 was obtained. The detection limit was 6.7 × 10(-9)M (at the ratio of signal to noise, S/N=3:1). The modified electrode also exhibited very good stability and reproducibility for the detection of ACOP. The established method was applied to the determination of ACOP in samples. An average recovery of 100.1% was achieved. These results indicated that this method was reliable for determining ACOP.     

Nonenzymatic electrochemical detection of glucose using well-distributed nickel nanoparticles on straight multi-walled carbon nanotubes

A nonenzymatic electrochemical sensor device was fabricated for glucose detection based on nickel nanoparticles (NiNPs)/straight multi-walled carbon nanotubes (SMWNTs) nanohybrids, which were synthesized through in situ precipitation procedure. SMWNTs can be easily dispersed in solution after mild sonication pretreatment, which facilitates the precursor of NiNPs binding to their surface and results in the homogeneous distribution of NiNPs on the surface of SMWNTs. The morphology and component of the nanohybrids were characterized by scanning electron microscopy (SEM) and X-ray powder diffraction (XRD), respectively. Cyclic voltammetry (CV) and amperometry were used to evaluate the catalytic activity of the NiNPs/SMWNTs nanohybrids modified electrode towards glucose. It was found that the nanohybrids modified electrode showed remarkably enhanced electrocatalytic activity towards the oxidation of glucose in alkaline solution compared to that of the bare glass carbon electrode (GCE), the NiNPs and the SMWNTs modified electrode, attributing to the synergistic effect of SMWNTs and Ni²⁺/Ni³⁺ redox couple. Under the optimal detection conditions, the as-prepared sensors exhibited linear behavior in the concentration range from 1 μM to 1 mM for the quantification of glucose with a limit of detection of 500 nM (3σ). Moreover, the NiNPs/SMWNTs modified electrode was also relatively insensitive to commonly interfering species such as ascorbic acid (AA), uric acid (UA), dopamine (DA), galactose (GA), and xylose (XY). The robust selectivities, sensitivities, and stabilities determined experimentally indicated the great potential of NiNPs/SMWNTs nanohybrids for construction of a variety of electrochemical sensors.