Regeneration, derivatization and utilization of cellulose in ultrathin films

Buchholz, Vera; Wegner, Gerhard; Stemme, Sara; Ödberg, Lars

doi:10.1002/adma.19960080504

Cited by 69 publications

(10 citation statements)

References 10 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1,24 Several strategies can be adopted to overcome this problem, including controlling the volume of reactants and the sample's wicking velocity. 25 Among those directed to the immobilization of the enzymes via chemical modication to the cellulose [26][27][28] it is worth mentioning the addition of succinic anhydride, 29 sodium periodate, 30 or 3-aminopropyltrimethoxysilane. 31 These modications result in the formation of carbonyl, aldehyde, or amino groups that can be used to permanently immobilize enzymes using covalent bonds and well-known conditions.…”

Section: Introductionmentioning

confidence: 99%

Modification of microfluidic paper-based devices with silica nanoparticles

Evans

Gabriel

Benavidez

et al. 2014

Analyst

143

View full text Add to dashboard Cite

This paper describes a silica nanoparticle-modified microfluidic paper-based analytical device (μPAD) with improved color intensity and uniformity for three different enzymatic reactions with clinical relevance (lactate, glucose, and glutamate). The μPADs were produced on Whatman grade 1 filter paper and using a CO2 laser engraver. Silica nanoparticles modified with 3-aminopropyltriethoxysilane (APTES) were then added to the paper devices to facilitate the adsorption of selected enzymes and prevent the washing away effect that creates color gradients in the colorimetric measurements. Here we show three different enzymatic assays for compounds. According to the results herein described, the addition of silica nanoparticles yielded to significant improvements in color intensity and uniformity. The resulting μPADs allowed for the detection of the three analytes in clinically-relevant concentration ranges with limits of detection (LOD) of 0.63 mM, 0.50 mM, and 0.25 mM for lactate, glucose, and glutamate, respectively. An example of an analytical application has been demonstrated for the semi-quantitative detection of all three analytes in artificial urine. The results demonstrate the potential of silica nanoparticles to avoid the washing away effect and improve the color uniformity and intensity in colorimetric bioassays performed on μPADs.

show abstract

Section: Introductionmentioning

confidence: 99%

Modification of microfluidic paper-based devices with silica nanoparticles

Evans

Gabriel

Benavidez

et al. 2014

Analyst

143

View full text Add to dashboard Cite

show abstract

“…Unfunctionalised cellulose can be regenerated by exposure to HCl vapour. The properties of the deposited surface have been characterised extensively by IR spectroscopy, surface plasmon resonance, ellipsometry, surface force measurements and photoelectron spectroscopy, [16,20,21] providing thicknesses of 10Å per layer for TMSC and 4Å per layer for the regenerated cellulose, showing that the charge on the cellulose chains is minimal (based on the absence of a double-layer force) and that the removal of the TMS groups is essentially complete.…”

Section: Introductionmentioning

confidence: 99%

Surfactant adsorption by total internal reflection Raman spectroscopy. Part III: Adsorption onto cellulose

Woods

Petkov

Bain

2011

Colloids and Surfaces A: Physicochemical and Engineering Aspect

View full text Add to dashboard Cite

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract TIR Raman spectroscopy has been used to study the adsorption of surfactants onto cellulose. The cellulose was prepared by Langmuir-Blodgett deposition of trimethylsilylcellulose onto silica followed by removal of the trimethylsilyl groups with acid to generate a hydrophilic surface. The reaction was followed in situ with Raman spectroscopy, revealing a two-step hydrolysis. Adsorption isotherms of hexadecyltrimethylammonium bromide (CTAB) and Triton X-100(TX-100) on hydrophilic cellulose were obtained by TIR Raman scattering under quasi-equilibrium conditions where the bulk concentration was slowly but continuously varied. The isotherms of both surfactants are almost linear, in contrast to the isotherms on hydrophilic silica. The CTAB isotherm shows hysteresis depending on whether the concentration of the surfactant is increasing or decreasing due to a slow adsorption region. A mixture of TX-100 and CTAB shows ideal adsorption, in contrast to adsorption of the same mixture on silica where there is a strong cooperative interaction at low CTAB surface coverage.

show abstract

“…Both types of TMSC films (LS and SC) were converted to cellulose via desilylation in humid HCl (g) atmosphere for 2 min. 32,33 These thin films were very sensitive to contamination and variation in relative humidity in the air and thus the desilylated films were stored in a dark desiccator for at least 48 hours, but not more than 100 hours prior to water vapour uptake measurements, to ensure repeatable results. Atomic Force Microscopy (AFM).…”

Section: Preparation Of Trimethylsilyl Cellulose (Tmsc)mentioning

confidence: 99%