scholarly journals In situ quantification of poly(3-hydroxybutyrate) and biomass in Cupriavidus necator by a fluorescence spectroscopic assay

2022 ◽  
Author(s):  
Alexander Kettner ◽  
Matthias Noll ◽  
Carola Griehl
Keyword(s):  
Fluorescence Spectroscopy ◽  
Simultaneous Detection ◽  
Nile Red ◽  
Biomass Concentration ◽  
Cupriavidus Necator ◽  
Fluorescence Staining ◽  
Excitation Emission Matrix ◽  
Novel Approach ◽  
Correlation Models

Abstract Fluorescence spectroscopy offers a cheap, simple, and fast approach to monitor poly(3-hydroxybutyrate) (PHB) formation, a biodegradable polymer belonging to the biodegradable polyester class polyhydroxyalkanoates. In the present study, a fluorescence and side scatter-based spectroscopic setup was developed to monitor in situ biomass, and PHB formation of biotechnological applied Cupriavidus necator strain. To establish PHB quantification of C. necator, the dyes 2,2-difluoro-4,6,8,10,12-pentamethyl-3-aza-1-azonia-2-boranuidatricyclo[7.3.0.03,7]dodeca-1(12),4,6,8,10-pentaene (BODIPY493/503), ethyl 5-methoxy-1,2-bis(3-methylbut-2-enyl)-3-oxoindole-2-carboxylate (LipidGreen2), and 9-(diethylamino)benzo[a]phenoxazin-5-one (Nile red) were compared with each other. Fluorescence staining efficacy was obtained through 3D-excitation-emission matrix and design of experiments. The coefficients of determination were ≥ 0.98 for all three dyes and linear to the high-pressure liquid chromatography obtained PHB content, and the side scatter to the biomass concentration. The fluorescence correlation models were further improved by the incorporation of the biomass-related side scatter. Afterward, the resulting regression fluorescence models were successfully applied to nitrogen-deficit, phosphor-deficit, and NaCl-stressed C. necator cultures. The highest transferability of the regression models was shown by using LipidGreen2. The novel approach opens a tailor-made way for a fast and simultaneous detection of the crucial biotechnological parameters biomass and PHB content during fermentation. Key points • Intracellular quantification of PHB and biomass using fluorescence spectroscopy. • Optimizing fluorescence staining conditions and 3D-excitation-emission matrix. • PHB was best obtained by LipidGreen2, followed by BODIPDY493/503 and Nile red. Graphical abstract

scholarly journals Plasmonic Technology: Novel Approach to Ultrasensitive Immunoassays

2005 ◽  
Vol 51 (10) ◽  
pp. 1914-1922 ◽  
Author(s):  
Joseph R Lakowicz ◽  
Joanna Malicka ◽  
Evgenia Matveeva ◽  
Ignacy Gryczynski ◽  
Zygmunt Gryczynski
Keyword(s):  
Fluorescence Spectroscopy ◽  
Surface Plasmons ◽  
Surface Plasmon ◽  
Spectral Properties ◽  
Simultaneous Detection ◽  
Dense Medium ◽  
Metallic Structures ◽  
Fluorescent Marker ◽  
Novel Approach ◽  
And Performance

Abstract At the Center for Fluorescence Spectroscopy, we have taken advantage of the favorable properties of surface plasmon-coupled emission (SPCE) to improve fluorescence-based immunoassays. SPCE occurs when excited fluorophores near conducting metallic structures efficiently couple to surface plasmons. These surface plasmons, appearing as free electron oscillations in the metallic layer, produce electromagnetic radiation that preserves the spectral properties of fluorophores but is highly polarized and directional. SPCE immunoassays provide several advantages over other fluorescence-based methods. This review explains new approaches to fluorescence immunoassays, including our own use of SPCE for simultaneous detection of more than one fluorescent marker and performance of immunoassays in the presence of an optically dense medium, such as whole blood.

Fluorescence spectroscopy studies of crossed aldol reactions: a reactive Nile red dye reveals catalyst-dependent product formation

2020 ◽  
Vol 10 (16) ◽  
pp. 5579-5592
Author(s):  
Judith Bautista-Gomez ◽  
Abdulhafiz Usman ◽  
Man Zhang ◽  
Ryan J. Rafferty ◽  
Stefan H. Bossmann ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Nile Red ◽  
Product Formation ◽  
Aldol Reactions ◽  
Spectroscopy Studies ◽  
Red Dye ◽  
Dependent Product

A highly fluorescent, aldol-reactive derivative of the dye Nile red is synthesized and evaluated as an in situ probe of crossed aldol reactions.

Solid Phase Excitation-Emission Matrix Spectroscopy for In-Situ Chemical Analysis of Combustion Aerosols

2020 ◽  
Author(s):  
Gaurav Mahamuni ◽  
Jiayang He ◽  
Jay Rutherford ◽  
Byron Ockerman ◽  
Edmund Seto ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Cigarette Smoke ◽  
Forest Fires ◽  
Solid Phase ◽  
Incident Angle ◽  
Personal Exposure ◽  
Traffic Emission ◽  
Excitation Emission Matrix ◽  
Internal Excitation

<p>Exposure to combustion generated aerosols such as PM from residential woodburning, forest fires, cigarette smoke, and traffic emission have been linked to adverse health outcomes. It is important to assess the chemical composition of PM to examine personal exposure. Excitation-emission matrix (EEM) spectroscopy has been shown as a sensitive and cost-effective technique for evaluation of combustion PM composition and as a source apportionment tool. However, EEM measurements are hindered by a solvent extraction step and a need for benchtop instrumentation. Here, we present a methodology that eliminates this labor-intensive sample preparation and allows to automate and miniaturize the detection platform. A miniature electrostatic collector deposits PM sample onto transparent polydimethylsiloxane (PDMS) coated substrate, where PAH components are extracted into solid-phase (SP) solvent and analyzed using EEM spectroscopy in-situ. We evaluated external and internal excitation schemes to optimized signal to noise ratio. Analysis of woodsmoke and cigarette smoke samples showed good agreement with liquid extraction EEM spectra. Internal excitation is hindered by fluorescent interference from PDMS at λ<250nm. The external excitation EEM spectra are dependent on the incident angle; ranges of 30-40⁰ and 55-65⁰ showed the best results. The proposed SP-EEM technique can be used for development of miniaturized sensors for chemical analysis of combustion generated PM. </p>

A novel approach for preparing in-situ nitrogen doped carbon via pyrolysis of bean pulp for supercapacitors

Energy ◽  
2021 ◽  
Vol 216 ◽  
pp. 119227
Author(s):  
Yan Ding ◽  
Yunchao Li ◽  
Yujie Dai ◽  
Xinhong Han ◽  
Bo Xing ◽  
...  
Keyword(s):  
Nitrogen Doped ◽  
Novel Approach ◽  
Nitrogen Doped Carbon

scholarly journals Ghost QTL and hotspots in experimental crosses: novel approach for modeling polygenic effects

Genetics ◽  
2021 ◽  
Author(s):  
Jonas Wallin ◽  
Małgorzata Bogdan ◽  
Piotr A Szulc ◽  
R W Doerge ◽  
David O Siegmund
Keyword(s):  
Recombinant Inbred Lines ◽  
Simultaneous Detection ◽  
Selection Strategy ◽  
Strongly Correlated ◽  
Mixed Effect ◽  
Novel Approach ◽  
Effect Model ◽  
Multiple Qtl ◽  
Sample Correlation ◽  
False Discoveries

Abstract Ghost quantitative trait loci (QTL) are the false discoveries in QTL mapping, that arise due to the “accumulation” of the polygenic effects, uniformly distributed over the genome. The locations on the chromosome that are strongly correlated with the total of the polygenic effects depend on a specific sample correlation structure determined by the genotypes at all loci. The problem is particularly severe when the same genotypes are used to study multiple QTL, e.g. using recombinant inbred lines or studying the expression QTL. In this case, the ghost QTL phenomenon can lead to false hotspots, where multiple QTL show apparent linkage to the same locus. We illustrate the problem using the classic backcross design and suggest that it can be solved by the application of the extended mixed effect model, where the random effects are allowed to have a nonzero mean. We provide formulas for estimating the thresholds for the corresponding t-test statistics and use them in the stepwise selection strategy, which allows for a simultaneous detection of several QTL. Extensive simulation studies illustrate that our approach eliminates ghost QTL/false hotspots, while preserving a high power of true QTL detection.

scholarly journals In Situ Generation of Green Hybrid Nanofibrillar Polymer-Polymer Composites—A Novel Approach to the Triple Shape Memory Polymer Formation

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1900
Author(s):  
Ramin Hosseinnezhad ◽  
Iurii Vozniak ◽  
Fahmi Zaïri
Keyword(s):  
Polymer Blends ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Cellulose Nanofibers ◽  
Polymeric Materials ◽  
Novel Approach ◽  
Phase Transition Temperatures ◽  
Triple Shape Memory

The paper discusses the possibility of using in situ generated hybrid polymer-polymer nanocomposites as polymeric materials with triple shape memory, which, unlike conventional polymer blends with triple shape memory, are characterized by fully separated phase transition temperatures and strongest bonding between the polymer blends phase interfaces which are critical to the shape fixing and recovery. This was demonstrated using the three-component system polylactide/polybutylene adipateterephthalate/cellulose nanofibers (PLA/PBAT/CNFs). The role of in situ generated PBAT nanofibers and CNFs in the formation of efficient physical crosslinks at PLA-PBAT, PLA-CNF and PBAT-CNF interfaces and the effect of CNFs on the PBAT fibrillation and crystallization processes were elucidated. The in situ generated composites showed drastically higher values of strain recovery ratios, strain fixity ratios, faster recovery rate and better mechanical properties compared to the blend.

scholarly journals A Novel Cobalt Metallopolymer with Redox-Matched Conjugated Organic Backbone via Electropolymerization of a Readily Available N4 Cobalt Complex

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1667
Author(s):  
Mikhail Karushev
Keyword(s):  
Redox Reactions ◽  
Repeat Unit ◽  
Cobalt Complex ◽  
Radical Cations ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Practical Applications ◽  
Sensing Applications ◽  
Novel Approach ◽  
Redox Switching

Fast and reversible cobalt-centered redox reactions in metallopolymers are the key to using these materials in energy storage, electrocatalytic, and sensing applications. Metal-centered electrochemical activity can be enhanced via redox matching of the conjugated organic backbone and cobalt centers. In this study, we present a novel approach to redox matching via modification of the cobalt coordination site: a conductive electrochemically active polymer was electro-synthesized from [Co(Amben)] complex (Amben = N,N′-bis(o-aminobenzylidene)ethylenediamine) for the first time. The poly-[Co(Amben)] films were investigated by cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM), in situ UV‑vis-NIR spectroelectrochemistry, and in situ conductance measurements between −0.9 and 1.3 V vs. Ag/Ag+. The polymer displayed multistep redox processes involving reversible transfer of the total of 1.25 electrons per repeat unit. The findings indicate consecutive formation of three redox states during reversible electrochemical oxidation of the polymer film, which were identified as benzidine radical cations, Co(III) ions, and benzidine di-cations. The Co(II)/Co(III) redox switching is retained in the thick polymer films because it occurs at potentials of high polymer conductivity due to the optimum redox matching of the Co(II)/Co(III) redox pair with the organic conjugated backbone. It makes poly-[Co(Amben)] suitable for various practical applications based on cobalt-mediated redox reactions.

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