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291.
LJ Hubble E Chow JS Cooper M Webster KH Müller L Wieczorek B Raguse 《Lab on a chip》2012,12(17):3040-3048
Functionalised gold nanoparticle (Au(NP)) chemiresistors are investigated for direct sensing of small organic molecules in biological fluids. The principle reason that Au(NP) chemiresistors, and many other sensing devices, have limited operation in biological fluids is due to protein and lipid fouling deactivating the sensing mechanism. In order to extend the capability of such chemiresistor sensors to operate directly in biofluids, it is essential to minimise undesirable matrix effects due to protein and lipidic components. Ultrafiltration membranes were investigated as semi-permeable size-selective barriers to prevent large biomolecule interactions with Au(NP) chemiresistors operating in protein-loaded biofluids. All of the ultrafiltration membranes protected the Au(NP) chemiresistors from fouling by the globular biomolecules, with the 10 kDa molecular weight cut-off size being optimum for operation in biofluids. Titrations of toluene in different protein-loaded fluids indicated that small molecule detection was possible. A sensor array consisting of six different thiolate-functionalised Au(NP) chemiresistors protected with a size-selective ultrafiltration membrane successfully identified, and discriminated the spoilage of pasteurised bovine milk. This proof-of-principle study demonstrates the on-chip protein separation and small metabolite detection capability, illustrating the potential for this technology in the field of microbial metabolomics. Overall, these results demonstrate that a sensor array can be protected from protein fouling with the use of a membrane, significantly increasing the possible application areas of Au(NP) chemiresistors ranging from the food industry to health services. 相似文献
292.
Dagmara Jacewicz Dariusz Wyrzykowski Krzysztof ?amoj? Diana Czerwińska Paulina Czaja Lech Chmurzyński 《Structural chemistry》2012,23(2):333-340
The thermal decomposition of trans-K[Cr(C2O4)2(OH2)2]·3H2O and cis-K[Cr(C2O4)2(OH2)2] has been studied using the TG–MS technique. The measurements were carried out in an argon atmosphere over the temperature
range of 293–873 K. The influence of the complex structures and configurational geometry on the stability of the transition
products and the pathways of thermal transformations has been discussed. Furthermore, the kinetics of the isomerization reactions
of the [Cr(C2O4)2(OH2)2]− complex ion catalyzed by five different metal ions: Be2+, Mg2+, Ca2+, Sr2+ and Ba2+ have been studied. The isomerization reactions were studied in aqueous solution at five various temperatures (283–303 K),
at constant concentration of metal ions (C = 0.1 M) and the constant ionic strength of solution (Na+, NO3
−) I = 2.4 M. The rates of the isomerization reaction were determined spectrophotometrically by monitoring of absorbance changes
at 410 nm. 相似文献
293.
Lech Zarȩba 《NoDEA : Nonlinear Differential Equations and Applications》2009,16(4):445-467
In this paper we consider the mixed problem for the equation u
tt
+ A
1
u + A
2(u
t
) + g(u
t
) = f(x, t) in unbounded domain, where A
1 is a linear elliptic operator of the fourth order and A
2 is a nonlinear elliptic operator of the second order. Under natural assumptions on the equation coefficients and f we proof existence of a solution. This result contains, as a special case, some of known before theorems of existence. Essentially,
in difference up to previous results we prove theorems of existence without the additional assumption on behavior of solution
at infinity.
相似文献