| 1. |
- Härma, Harri, et al.
(författare)
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Rapid detection of trace amounts of surfactants using nanoparticles in fluorometric assays
- 2010
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Ingår i: Nanoscale. - Cambridge (Thomas Graham House), UK : The Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 2:1, s. 69-71
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Tidskriftsartikel (refereegranskat)abstract
- Rapid microtiter assays that utilize the time-resolved fluorescenceresonance energy transfer or quenching of dye-labeled proteinsadsorbed onto the surfaces of polystyrene or maghemite nanoparticleshave been developed for the detection and quantification oftrace amounts of surfactants at concentrations down to 10 nM.
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| 2. |
- Högmander, Milla, et al.
(författare)
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Luminometric Label Array for Counting and Differentiation of Bacteria
- 2017
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 89:5, s. 3208-3216
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Tidskriftsartikel (refereegranskat)abstract
- Methods for simple and fast detection and differentiation of bacterial species are required, for instance, in medicine, water quality monitoring, and the food industry. Here, we have developed a novel label array method for the counting and differentiation of bacterial species. This method is based on the nonspecific interactions of multiple unstable lanthanide chelates and selected chemicals within the sample leading to a luminescence signal profile that is unique to the bacterial species. It is simple, cost-effective, and/or user-friendly compared to many existing methods, such as plate counts on selective media, automatic (hemocytometer-based) cell counters, flow cytometry, and polymerase chain reaction (PCR)-based methods for identification. The performance of the method was demonstrated with nine single strains of bacteria in pure culture. The limit of detection for counting was below 1000 bacteria per mL, with an average coefficient of variation of 10% achieved with the developed label array. A predictive model was trained with the measured luminescence signals and its ability to differentiate all tested bacterial species from each other, including members of the same genus Bacillus licheniformis and Bacillus subtilis, was confirmed via leave-one-out cross-validation. The suitability of the method for analysis of mixtures of bacterial species was shown with ternary mixtures of Bacillus licheniformis, Escherichia coli JM109, and Lactobacillus reuteri ATCC PTA 4659. The potential future application of the method could be monitoring for contamination in pure cultures; analysis of mixed bacterial cultures, where examining one species in the presence of another could inform industrial microbial processes; and the analysis of bacterial biofilms, where nonspecific methods based on physical and chemical characteristics are required instead of methods specific to individual bacterial species.
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| 3. |
- Norrbo, Isabella, et al.
(författare)
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Lanthanide and Heavy Metal Free Long White Persistent Luminescence from Ti Doped Li-Hackmanite : A Versatile, Low-Cost Material
- 2017
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 27:17
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Tidskriftsartikel (refereegranskat)abstract
- Persistent luminescence (PeL) materials are used in everyday glow-in-the-dark applications and they show high potential for, e.g., medical imaging, night-vision surveillance, and enhancement of solar cells. However, the best performing materials contain rare earths and/or other heavy metal and expensive elements such as Ga and Ge, increasing the production costs. Here, (Li,Na)(8)Al6Si6O24(Cl,S)(2):Ti, a heavy-metal-and rare-earth-free low-cost material is presented. It can give white PeL that stays 7 h above the 0.3 mcd m(-2) limit and is observable for more than 100 h with a spectrometer. This is a record-long duration for white PeL and visible PeL without rare earths. The material has great potential to be applied in white light emitting devices (LEDs) combined with self-sustained night vision using only a single phosphor. The material also exhibits PeL in aqueous suspensions and is capable of showing easily detectable photoluminescence even in nanomolar concentrations, indicating potential for use as a diagnostic marker. Because it is excitable with sunlight, this material is expected to additionally be well-suited for outdoor applications.
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