scholarly journals Development of Amperometric Laccase Biosensor through Immobilizing Enzyme in Magnesium-Containing Mesoporous Silica Sieve (Mg-MCM-41)/Polyvinyl Alcohol Matrix

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Z. Dai ◽  
M. Q. Guo ◽  
X. J. Wang ◽  
H. F. Wang ◽  
W. Y. Chen
Keyword(s):  
Mesoporous Silica ◽  
High Surface ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Surface Areas ◽  
Long Time ◽  
Good Biocompatibility ◽  
Laccase Immobilization ◽  
Mcm 41

Magnesium-containing mesoporous silica sieve (Mg-MCM-41) provided a suitable immobilization of biomolecule matrix due to its uniform pore structure, high surface areas, fast electron-transfer rate, and good biocompatibility. Based on this, an amperometric biosensor was developed by entrapping laccase into the Mg-MCM-41/PVA composite matrix. Laccase from Trametes versicolor was assembled on a composite film of Mg-MCM-41/PVA modified Au electrode and the electrode was investigated by cyclic voltammetry, impedance spectroscopy, and chronoamperometry. The results indicated that the Mg-MCM-41/PVA/Lac modified electrode exhibited excellent catalytic activity towards catechol at room temperature in pH 4.8 acetate buffer solution. The optimum experimental conditions of biosensor for the detection of catechol were studied in detail. Under the optimal conditions, the linear range was from 0.94 to 10.23 μM with the sensitivity of 16.9227 A/M, the detection limit of 0.00531 μM, and the response time of less than 14 s. The Michaelis-Menten constant (KMapp) was estimated by Lineweaver-Burk equation and theKMappvalue was about 1.01 μM. In addition, the biosensor exhibited high reproducibility and long-time stability. This work demonstrated that Mg-MCM-41/PVA composite provides a suitable support for laccase immobilization and construction of biosensor.

Strategies to Regulate the Degradability of Mesoporous Silica-based Nanoparticles for Biomedical Applications

NANO ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. 1930008 ◽  
Author(s):  
Xiangye Li ◽  
Feixue Gao ◽  
Yunhui Dong ◽  
Xinjin Li
Keyword(s):  
Mesoporous Silica ◽  
Biomedical Applications ◽  
High Surface ◽  
Effective Solution ◽  
Effective Strategies ◽  
Major Threat ◽  
Surface Areas ◽  
Good Biocompatibility ◽  
Therapy Strategies ◽  
Effective Cancer Therapy

Cancer is the second major threat to human health, and more effective cancer therapy strategies are imperative. With the development of nanotechnology, mesoporous silica-based nanoparticles (MSNs) have seen unprecedented development in cancer treatment, such as drug delivery, bioimaging and biosensing. They have received extensive attention because of their easy preparation, adjustable morphology, homogeneous pore structure, high surface areas and good biocompatibility. However, cumulative toxicity for organism caused by the low degradability of MSNs heavily hinders their translation from bench to beside. Enhancing the degradability of MSNs has provided an effective solution to solve this problem. This review aims at summarizing the effective strategies utilized to regulate the degradability of MSNs during the last few years, giving a complete overview on the recent progress and remaining challenges of degradable MSNs.

Robust transparent mesoporous silica membranes as matrices for colorimetric sensors

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16549-16553 ◽  
Author(s):  
Donghun Kim ◽  
Bradley F. Chmelka
Keyword(s):  
Heavy Metal ◽  
Mesoporous Silica ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Colorimetric Detection ◽  
High Surface ◽  
Silica Membranes ◽  
Surface Areas ◽  
Functionalized Mesoporous Silica ◽  
Colorimetric Sensors

Transparent functionalized mesoporous silica membranes have been prepared with high surface areas (∼500 m2 g−1) that exhibit high sensitivities for colorimetric detection and sensing of dilute heavy-metal ions (e.g., Pb2+).

scholarly journals An Assessment of Mesoporous Silica Nanoparticle Architectures as Antigen Carriers

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 294 ◽  
Author(s):  
Xinyue Huang ◽  
Helen E Townley
Keyword(s):  
Mesoporous Silica ◽  
Mesoporous Silica Nanoparticles ◽  
High Surface ◽  
Silica Nanoparticle ◽  
Storage Conditions ◽  
Surface Areas ◽  
Antigen Complex ◽  
The Stability ◽  
And Storage ◽  
Storage Temperatures

Mesoporous silica nanoparticles (MSNPs) have the potential to be used as antigen carriers due to their high surface areas and highly ordered pore network. We investigated the adsorption and desorption of diphtheria toxoid as a proof-of-concept. Two series of nanoparticles were prepared—(i) small pores (SP) (<10 nm) and (ii) large pores (LP) (>10 nm). SBA-15 was included as a comparison since this is commercially available and has been used in a large number of studies. External diameters of the particles ranged from 138 to 1509 nm, surface area from 632 to 1110 m2/g and pore size from 2.59 to 16.48 nm. Antigen loading was assessed at a number of different ratios of silica-to-antigen and at 4 °C, 20 °C and 37 °C. Our data showed that protein adsorption by the SP series was in general consistently lower than that shown by the large pore series. Unloading was then examined at 4 °C, 20 °C and 37 °C and a pH 1.2, 4.5, 6.8 and 7.4. There was a trend amongst the LP particles towards the smallest pores showing the lowest release of antigen. The stability of the MSNP: antigen complex was tested at two different storage temperatures, and storage in solution or after lyophilization. After 6 months there was negligible release from any of the particles under any of the storage conditions. The particles were also shown not to cause hemolysis.

scholarly journals Metal Nanoparticles Supported on Al-MCM-41 via In Situ Aqueous Synthesis

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Ivonne Alonso-Lemus ◽  
Ysmael Verde-Gomez ◽  
Alfredo Aguilar-Elguézabal ◽  
Lorena Álvarez-Contreras
Keyword(s):  
Metallic Nanoparticles ◽  
High Surface ◽  
Textural Properties ◽  
Active Phase ◽  
Ruthenium Catalysts ◽  
Aqueous Synthesis ◽  
Surface Areas ◽  
Electrochemical Testing ◽  
Size And Morphology ◽  
Mcm 41

MCM-41 have been used to custom synthesize catalysts in because of the controllable properties, such as pore size, active phase incorporation, crystal size, and morphology, among others. In this paper, a simple and versatile method for the incorporation of platinum, ruthenium, and palladium onto Al-MCM-41 mesoporous silica by direct inclusion of various precursors was studied. M/Al-MCM-41 structure, textural properties, morphology, and elemental composition were analyzed. The results obtained indicate that the Al-MCM-41 mesoporous-ordered structure was not affected by metallic particle incorporation. High-surface areas were obtained (1131 m2/g). Metallic nanoparticles dispersion on Al-MCM-41 was homogeneous for all samples and its particles sizes were between 6 nm to 20 nm. Microscopy results show round shape particles in platinum and palladium samples; however, ruthenium catalysts exhibit a spherical and rod shapes. Electrochemical testing for Pt/Al-MCM-41 showed electrocatalytic activity forH2oxidation which indicates that these materials can be used as a catalyst in electrochemical devices.

Novel method to synthesize ordered mesoporous silica with high surface areas

2008 ◽  
Vol 10 (4) ◽  
pp. 408-415 ◽  
Author(s):  
Montserrat Colilla ◽  
Francisco Balas ◽  
Miguel Manzano ◽  
María Vallet-Regí
Keyword(s):  
Mesoporous Silica ◽  
High Surface ◽  
Ordered Mesoporous Silica ◽  
Surface Areas ◽  
Ordered Mesoporous ◽  
Novel Method

Analysis of conditions for the preparation of BSA/MMT composites

2013 ◽  
Vol 20 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Yinghai Lv ◽  
Xiaolu Su ◽  
Fuli Ren ◽  
Hong-qiang Kan ◽  
Ying Kong
Keyword(s):  
Ionic Strength ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Ph Values ◽  
Fixation Effect ◽  
The Impact ◽  
Adsorption Quantity ◽  
Better Than

AbstractThis study describes a new method for protein fixation that has high, stable, and good repeatable fixation effect without deactivating protein. This method involves intercalating bovine serum albumin (BSA) into montmorillonite (MMT) under different experimental conditions, i.e., the concentration of coupling agent KH570, pH values, ionic strength, and the impact of buffers. The study showed the interaction of buffer systems with pH values had the most significant influence on adsorption quantity. The existence of the buffer increased the adsorption quantity and helped with slow protein releasing, while the phosphate buffer worked better than acetate buffer. More BSA was adsorbed on KH570 treated than untreated MMT, and among the treated samples the most protein released was on MMT treated with KH570 in 100% ethanol and in the acetate buffer solution. Adsorption quantity of the BSA initially increased and then decreased with the increase of the ionic strength. The research on the preparation of MMT/BSA materials provides further information on the study of protein composites.

pH-Responsive sulphonated mesoporous silica: a comparative drug release study

RSC Advances ◽  
2016 ◽  
Vol 6 (63) ◽  
pp. 57929-57940 ◽  
Author(s):  
Mohamad M. Ayad ◽  
Nehal A. Salahuddin ◽  
Nagy L. Torad ◽  
Ahmed Abu El-Nasr
Keyword(s):  
Drug Release ◽  
Mesoporous Silica ◽  
Surface Functionalization ◽  
High Surface ◽  
Ph Responsive ◽  
Drug Release Study ◽  
Surface Areas ◽  
Silica Materials ◽  
Mesoporous Silica Materials ◽  
Release Study

Control of morphology and surface functionalization of mesoporous silica materials have enhanced the biocompatibility of these materials with high surface areas and total pore volumes.

scholarly journals Spectrophotometric Estimation of Cefuroxime and Ceftazidime in Bulk and in Dosage Forms

2001 ◽  
Vol 69 (2) ◽  
pp. 143-150 ◽  
Author(s):  
A. Amin ◽  
H. Khalli ◽  
H. Saleh
Keyword(s):  
Molar Absorptivity ◽  
Dosage Forms ◽  
Acetate Buffer Solution ◽  
Sodium Fluorescein ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Optimum Concentration Range

Three simple, accurate and sensitive spectrophotometric methods (A, B and C) for the determination of cefuroxime and ceftazidime in bulk samples and in dosage forms are described. They are based on the reaction with nitrous acid forming a nitroso derivatives which can be measured at λmax 350 and 355 nm for cefuroxime (I) and ceftazidime (II), respectively (method A) or by oxidation of drug I or II with an excess of freshly prepared hypobromite and the residual hypobromite was treated with sodium fluorescein at the optimum experimental conditions and measured at λmax at 517 nm (method B). Method C is based on the formation of tris (0-phenanthroline) iron(II) complex (ferroin) upon the oxidation of the studied drug I or II with an iron (III)-o-phenanthroline mixture in acetate buffer solution of pH 3.6 and measuring at λmax 509 nm. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 0.2 – 6.0, 0.2 – 3.2 and 0.1 – 5.6 μg ml−1 for methods A, B and C, respectively. The apparent molar absorptivity, Sandell sensitivity, detection and quantitation limits were calculated. For more accurate results, Ringbom optimum concentration range was 0.2 – 5.6 μg ml−1. The validity of the proposed methods was tested by analysing dosage forms containing the studied drugs I and II. The relative standard deviations were ≤ 1.25% with recoveries 98.6 – 101.4% .

scholarly journals Adsorption/reduction of N-dimethylnitrosamine from aqueous solution using nano zero-valent iron nanoparticles supported on ordered mesoporous silica

2017 ◽  
Vol 17 (4) ◽  
pp. 1097-1105 ◽  
Author(s):  
Xiaodong Xin ◽  
Shaohua Sun ◽  
Mingquan Wang ◽  
Qinghua Zhao ◽  
Yan Chen ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Iron Nanoparticles ◽  
Catalytic Reduction ◽  
High Surface ◽  
High Surface Area ◽  
Zero Valent Iron ◽  
Product Analysis ◽  
Solution Ph ◽  
Zero Valent Iron Nanoparticles ◽  
Mcm 41

N-Dimethylnitrosamine (NDMA) has aroused increasing concern among public health agencies. It is necessary to develop some effective methods to remove NDMA from drinking water. A reductive process has been investigated as an alternative treatment method for NDMA removal from water. In this manuscript, zero-valent iron nanoparticles (ZVINPs) were synthesized, and then supported on mesoporous silica materials with high surface area (MCM-41) to prepare a stable ZVINP/MCM-41 nanocomposite. X-ray diffraction measurements showed the stabilization of the ZVINPs upon their support on MCM-41, which enhanced their activity. The ZVINP/MCM-41 nanocomposite was used for the catalytic reduction of NDMA in the model solution, and the results showed the dependency of the removal process on the ZVINP/MCM-41 mass, time of removal, and solution pH. The mechanism of NDMA reduction by ZVINP/MCM-41 was studied, and the results showed the conversion of NDMA to unsymmetrical dimethylhydrazine, dimethylamine (DMA) and NH4+. The product analysis found that in the process of removal, adsorption and reduction existed at the same time.

The Synthesis of High-Surface Area Silicon Carbide by Conversion Method Using Carbosilane Polymer

2014 ◽  
Vol 353 ◽  
pp. 244-247
Author(s):  
Eun Jin Jung ◽  
Yoon Joo Lee ◽  
Woo Teck Kwon ◽  
Y. Kim ◽  
Dong Geun Shin ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Mesoporous Silica ◽  
Surface Area ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Bet Analysis ◽  
Fibrous Morphology ◽  
High Surface Area Materials ◽  
Mcm 41

Since mesoporous silica such as MCM-41 and SBA-15 was developed, the study of the properties of high-surface area materials was accelerated. Moreover, the mesoporous silica is used as a template to produce high-surface materials by nanocasting technology. The purpose of this paper is the synthesis of a high surface silicon carbide sphere by the nanocasting technology. In this study, KCC-1 silica sphere was used as a template, and polycarbosilane and poly (phenyl carbosilane) were selected for precursor of silicon carbide. Carbosilane polymer gives advantage of synthesis silicon carbide under low temperature, and hollow spheres were produced. In this study, the polycarbosilane was more effective for the synthesis of SiC hollow spheres by inversion of template structure showing a fibrous morphology on the sphere wall. And it was confirmed that the sphere was composed of nanosized SiC crystals, and has high surface area using TEM, XRD and BET analysis.

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