Stable CdTe nanocrystals grown in situ in thiol-modified MCM-41 mesoporous silica: Control synthesis and electrochemical detection of Cu 2+

Santos, José Antonio; Matos, Charlene Regina Santos; Pereira, George Bueno Santana; Santana, Tiago B. S.; Souza, Helio O.; Costa, Luiz Pereira da; Sussuchi, Eliana Midori; Pedrosa, Anne Michelle Garrido; Gimenez, Iara F.

doi:10.1016/j.micromeso.2015.09.024

Cited by 15 publications

(4 citation statements)

References 53 publications

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“…Bare and modified electrodes were investigated by cyclic voltammetry in the presence of [Fe(CN) 6 ] 3−/4-. Figure 3d shows typical cyclic voltammograms for the [Fe(CN) 6 ] 3−/4-pair, exhibiting anodic (+0.27 V) and cathodic peak (−0.15 V), characteristic of this complex as widely described in the literature [31]. The separation between oxidation and reduction peaks for Bferri/ferroŝ ystem at bare carbon paste electrode was 200 mV, decreasing in the case of modified electrodes (120 mV for CPE/QD, 160 mV for CPE/QD-rGO and 170 mV for CPE/QD-GO), which indicates that the QD/composites can increase the electron transfer rate in the [Fe(CN) 6 ] 3−/4-pair.…”

Section: Interaction Of CD 1-x Mg X Te Nanocrystals With Graphene-basmentioning

confidence: 60%

Cd1-xMgxTe semiconductor nanocrystal alloys: Synthesis, preparation of nanocomposites with graphene-based materials, and electrochemical detection of lidocaine and epinephrine

et al. 2017

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This work describes the synthesis of a glutathione-capped Cd 1-x Mg x Te semiconductor nanocrystal alloy in aqueous solution. The effects of reaction time and Cd:Mg molar proportion on the spectroscopic and electrochemical properties were optimized. The Cd 1-x Mg x Te material was found to emit in the visible range (blueishgreen to dark pink), with the band gap energy depending both on the Mg:Cd ratio and of the nanocrystal size. The insitu growth of the nanocrystal alloy on both graphene oxide and reduced graphene oxide leads to partial quenching of the photoluminescence of Cd 1-x Mg x Te but improves the electrochemical response of the nanocrystals. Carbon paste electrodes (CPE) were modified with the graphene-based materials containing semiconductor nanocrystals, and it is shown that such a modified CPE can be applied to the determination of the local anesthetic lidocaine and the anaphylactic drug epinephrine via differential pulse voltammetry. Each analyte can be determined both individually and in the presence of constant concentrations of the other, best at typical oxidation potentials of 0.25 V and 1.0 V (vs. Ag/ AgCl), respectively. In the best cases, the detection limits are 92 nM for lidocaine and 0.95 μM for epinephrine.

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Section: Interaction Of CD 1-x Mg X Te Nanocrystals With Graphene-basmentioning

confidence: 60%

Cd1-xMgxTe semiconductor nanocrystal alloys: Synthesis, preparation of nanocomposites with graphene-based materials, and electrochemical detection of lidocaine and epinephrine

et al. 2017

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“…The magnetic core-shell nanoparticles were functionalized with MPTMS [32]. The Fe 3 O 4 @MCM-41 particles (5 g) were suspended in toluene followed by the addition of MPTMS (5 ml).…”

Section: Functionalization Of Fe 3 O 4 @Mcm-41 Nanocompositesmentioning

confidence: 99%

Magnetic Fe₃O₄@MCM-41 core–shell nanoparticles functionalized with thiol silane for efficient l-asparaginase immobilization

Ulu

Noma

Köytepe

et al. 2018

Artificial Cells, Nanomedicine, and Biotechnology

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l-Asparaginase (l-ASNase) is a vital enzyme for medical treatment and food industry. Here, we assessed the use of FeO@Mobil Composition of Matter No. 41 (MCM-41) magnetic nanoparticles as carrier matrix for l-ASNase immobilization. In addition, surface of FeO@MCM-41 magnetic nanoparticles was functionalized with 3-mercaptopropyltrimethoxysilane (MPTMS) to enhance stability of l-ASNase. The chemical structure, thermal properties, magnetic profile and morphology of the thiol-functionalized FeO@MCM-41 magnetic nanoparticles were characterized with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), differential scanning calorimetry (DSC), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray (EDX) spectroscopy and zeta-potential measurement. l-ASNase was covalently immobilized onto the thiol-functionalized FeO@MCM-41 magnetic nanoparticles. The properties of the immobilized enzyme, including optimum pH, temperature, kinetic parameters, thermal stability, reusability and storage stability were investigated and compared to free one. Immobilized enzyme was found to be stable over a wide range of pH and temperature range than free enzyme. The immobilized l-ASNase also showed higher thermal stability after 180 min incubation at 50 °C. The immobilized enzyme still retained 63% of its original activity after 16 times of reuse. The Km value for the immobilized enzyme was 1.15-fold lower than the free enzyme, which indicates increased affinity for the substrate. Additionally, the immobilized enzyme was active over 65% and 53% after 30 days of storage at 4 °C and room temperature (∼25 °C), respectively. Thereby, the results confirmed that thiol-functionalized FeO@MCM-41 magnetic nanoparticles had high efficiency for l-ASNase immobilization and improved stability of L-ASNase.

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“…For copper detection, the use of various materials such as functionalized polymers, drugs, fibers and silicas immobilized on carbon paste electrodes have been studied [13][14][15][16]. The literature reports a series of functionalized mesoporous materials for the removal and detection of copper ions as well as the development of new optical and electrochemical sensors [17][18][19]. The use of mesoporous material functionalized with 3-aminepropyltriethoxysilane (APTS) and 3aminepropyltrimethoxysilane (APMS) improve the efficiency of these materials for the detection of trace metals, specially copper, due chelating ability of the amine groups present on them.…”

Section: Introductionmentioning

confidence: 99%

Comparative study of mesopourous silica obtained by different synthetic routes to improve the analysis of Cu(II) in sugar cane spirit

et al. 2020

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Mesoporous silicas have properties that allow their wide chemical application, due to the large amount of silanol groups on their walls. The possibility of introducing functional groups inside and on the surface of their pores becomes viable the use of these functionalized mesoporous materials for the adsorption of metal ions. Cooper ions are essential for vital functions, but in high concentrations, they are responsible for causing problems to the human organism. Therefore, it is important to monitor the species in different media, such as sugar cane spirit. Mesoporous materials type MCM-41 functionalized were obtained by three different methods using direct (in situ) and indirect (post-synthesis) routes. The mesoporous materials have exhibited properties according to the IUPAC classification. Modified carbon paste electrodes (MCPEs) were prepared by immobilizing the synthesized materials for Cu2+ analysis. The modified electrode obtained by the immobilization of functionalized mesoporous R2 (MCPE/R2) presented the best sensitivity for Cu2+ detection. Under optimum experimental conditions, the MCPE/R2 exhibited a linear range in between 0.99 and 11.80 μmol L-1, a sensitivity based on the Limit of Detection (LOD) of 0.50 μmol L-1and Limit of Quantification (LOQ) of 0.99 μmol L-1, precision (DPRmáx) equals to 10.6% and recovery of 92.2%. The developed method proved to be efficient for Cu2+ determination in sugar cane spirit and the accuracy of the results were comparable to those obtained by AAS.

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Stable CdTe nanocrystals grown in situ in thiol-modified MCM-41 mesoporous silica: Control synthesis and electrochemical detection of Cu 2+

Cited by 15 publications

References 53 publications

Cd1-xMgxTe semiconductor nanocrystal alloys: Synthesis, preparation of nanocomposites with graphene-based materials, and electrochemical detection of lidocaine and epinephrine

Cd1-xMgxTe semiconductor nanocrystal alloys: Synthesis, preparation of nanocomposites with graphene-based materials, and electrochemical detection of lidocaine and epinephrine

Magnetic Fe₃O₄@MCM-41 core–shell nanoparticles functionalized with thiol silane for efficient l-asparaginase immobilization

Comparative study of mesopourous silica obtained by different synthetic routes to improve the analysis of Cu(II) in sugar cane spirit

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Stable CdTe nanocrystals grown in situ in thiol-modified MCM-41 mesoporous silica: Control synthesis and electrochemical detection of Cu 2+

Cited by 15 publications

References 53 publications

Cd1-xMgxTe semiconductor nanocrystal alloys: Synthesis, preparation of nanocomposites with graphene-based materials, and electrochemical detection of lidocaine and epinephrine

Cd1-xMgxTe semiconductor nanocrystal alloys: Synthesis, preparation of nanocomposites with graphene-based materials, and electrochemical detection of lidocaine and epinephrine

Magnetic Fe3O4@MCM-41 core–shell nanoparticles functionalized with thiol silane for efficient l-asparaginase immobilization

Comparative study of mesopourous silica obtained by different synthetic routes to improve the analysis of Cu(II) in sugar cane spirit

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Magnetic Fe₃O₄@MCM-41 core–shell nanoparticles functionalized with thiol silane for efficient l-asparaginase immobilization