scholarly journals Theoretical Modeling of Viscosity Monitoring with Vibrating Resonance Energy Transfer for Point-of-Care and Environmental Monitoring Applications

Micromachines ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 3 ◽  
Author(s):  
Gorkem Memisoglu ◽  
Burhan Gulbahar ◽  
Joseba Zubia ◽  
Joel Villatoro
Keyword(s):  
Energy Transfer ◽  
Environmental Monitoring ◽  
System Design ◽  
Point Of Care ◽  
Resonance Energy Transfer ◽  
Microfluidic Channel ◽  
Resonance Energy ◽  
Polluted Water ◽  
Hardware Complexity ◽  
Monitoring Applications

Förster resonance energy transfer (FRET) between two molecules in nanoscale distances is utilized in significant number of applications including biological and chemical applications, monitoring cellular activities, sensors, wireless communications and recently in nanoscale microfluidic radar design denoted by the vibrating FRET (VFRET) exploiting hybrid resonating graphene membrane and FRET design. In this article, a low hardware complexity and novel microfluidic viscosity monitoring system architecture is presented by exploiting VFRET in a novel microfluidic system design. The donor molecules in a microfluidic channel are acoustically vibrated resulting in VFRET in the case of nearby acceptor molecules detected with their periodic optical emission signals. VFRET does not require complicated hardware by directly utilizing molecular interactions detected with the conventional photodetectors. The proposed viscosity measurement system design is theoretically modeled and numerically simulated while the experimental challenges are discussed. It promises point-of-care and environmental monitoring applications including viscosity characterization of blood or polluted water.

scholarly journals Time-resolved Fluorescence Resonance Energy Transfer Assay for Point-of-Care Testing of Urinary Albumin

2003 ◽  
Vol 49 (7) ◽  
pp. 1105-1113 ◽  
Author(s):  
Qiu-Ping Qin ◽  
Olli Peltola ◽  
Kim Pettersson
Keyword(s):  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Time Resolved ◽  
Urine Albumin ◽  
Europium Chelate ◽  
Fluorescence Resonance

Abstract Background: Microalbuminuria is an established early marker of diabetic nephropathy and an important cardiovascular risk factor in diabetes and hypertension. We aimed to develop a rapid point-of-care assay for the measurement of urine albumin. Methods: The competitive homogeneous assay used an albumin-specific monoclonal antibody labeled with a stable fluorescent europium chelate as donor and an albumin labeled with cyanine 5 (Cy5) as acceptor. The assay was performed at room temperature in single microtitration wells that contained all the required dry-form reagents. The close proximity between the two labels in the immune complex allowed fluorescence resonance energy to be transferred from the pulse-excited europium chelate to the acceptor Cy5. The emission of long-lived energy transfer signal from the sensitized Cy5 was measured at 665 nm with time-resolved fluorometry that eliminated short-lived background. Results: The assay procedure required 12 min for a 10-μL urine sample. The working range was from 10 to ∼320 mg/L, and the lower limit of detection was 5.5 mg/L. The within- and between-run CVs were 6.9–10% and 7.5–13%, respectively. Recovery was 103–122%. The assay correlated well (r2 = 0.98; n = 37) with a laboratory-based immunoassay, although mean (SD) results were 7 (29)% lower. Conclusions: The speed and ease of performance of this assay recommend it for near-patient use. The assay is the first to combine a fluorescence resonance energy transfer-type rapid competitive assay with an all-in-one dry reagent.

Quantum Dot Bioconjugates as Energy Donors in Fluorescence Resonance Energy Transfer Assays

2003 ◽  
Vol 773 ◽  
Author(s):  
Aaron R. Clapp ◽  
Igor L. Medintz ◽  
J. Matthew Mauro ◽  
Hedi Mattoussi
Keyword(s):  
Energy Transfer ◽  
Quantum Dot ◽  
Organic Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Genetically Engineered ◽  
Molar Ratio ◽  
Binding Assays ◽  
Specific Sequence ◽  
Donor Acceptor

AbstractLuminescent CdSe-ZnS core-shell quantum dot (QD) bioconjugates were used as energy donors in fluorescent resonance energy transfer (FRET) binding assays. The QDs were coated with saturating amounts of genetically engineered maltose binding protein (MBP) using a noncovalent immobilization process, and Cy3 organic dyes covalently attached at a specific sequence to MBP were used as energy acceptor molecules. Energy transfer efficiency was measured as a function of the MBP-Cy3/QD molar ratio for two different donor fluorescence emissions (different QD core sizes). Apparent donor-acceptor distances were determined from these FRET studies, and the measured distances are consistent with QD-protein conjugate dimensions previously determined from structural studies.

Quantitative Ratiometric pH Imaging Using a 1,2-Dioxetane Chemiluminescence Resonance Energy Transfer Sensor

2020 ◽  
Author(s):  
Lucas S. Ryan ◽  
Jeni Gerberich ◽  
Uroob Haris ◽  
ralph mason ◽  
Alexander Lippert
Keyword(s):  
Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Whole Body ◽  
Photon Flux ◽  
Ph Homeostasis ◽  
Ph Imaging ◽  
Confounding Variables ◽  
Significant Difference

<p>Regulation of physiological pH is integral for proper whole-body and cellular function, and disruptions in pH homeostasis can be both a cause and effect of disease. In light of this, many methods have been developed to monitor pH in cells and animals. In this study, we report a chemiluminescence resonance energy transfer (CRET) probe Ratio-pHCL-1, comprised of an acrylamide 1,2-dioxetane chemiluminescent scaffold with an appended pH-sensitive carbofluorescein fluorophore. The probe provides an accurate measurement of pH between 6.8-8.4, making it viable tool for measuring pH in biological systems. Further, its ratiometric output is independent of confounding variables. Quantification of pH can be accomplished both using common fluorimetry and advanced optical imaging methods. Using an IVIS Spectrum, pH can be quantified through tissue with Ratio-pHCL-1, which has been shown in vitro and precisely calibrated in sacrificed mouse models. Initial studies showed that intraperitoneal injections of Ratio-pHCL-1 into sacrificed mice produce a photon flux of more than 10^10 photons per second, and showed a significant difference in ratio of emission intensities between pH 6.0, 7.0, and 8.0.</p> <b></b><i></i><u></u><sub></sub><sup></sup><br>

A Small Molecule – Protein Hybrid for Voltage Imaging via Quenching of Bioluminescence

2020 ◽  
Author(s):  
Brittany Benlian ◽  
Pavel Klier ◽  
Kayli Martinez ◽  
Marie Schwinn ◽  
Thomas Kirkland ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Membrane Potential ◽  
Small Molecule ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Live Cells ◽  
Potential Oscillations ◽  
Excitation Light ◽  
Voltage Imaging ◽  
Induced Pluripotent

<p>We report a small molecule enzyme pair for optical voltage sensing via quenching of bioluminescence. This <u>Q</u>uenching <u>B</u>ioluminescent V<u>olt</u>age Indicator, or Q-BOLT, pairs the dark absorbing, voltage-sensitive dipicrylamine with membrane-localized bioluminescence from the luciferase NanoLuc (NLuc). As a result, bioluminescence is quenched through resonance energy transfer (QRET) as a function of membrane potential. Fusion of HaloTag to NLuc creates a two-acceptor bioluminescence resonance energy transfer (BRET) system when a tetramethylrhodamine (TMR) HaloTag ligand is ligated to HaloTag. In this mode, Q-BOLT is capable of providing direct visualization of changes in membrane potential in live cells via three distinct readouts: change in QRET, BRET, and the ratio between bioluminescence emission and BRET. Q-BOLT can provide up to a 29% change in bioluminescence (ΔBL/BL) and >100% ΔBRET/BRET per 100 mV change in HEK 293T cells, without the need for excitation light. In cardiac monolayers derived from human induced pluripotent stem cells (hiPSC), Q-BOLT readily reports on membrane potential oscillations. Q-BOLT is the first example of a hybrid small molecule – protein voltage indicator that does not require excitation light and may be useful in contexts where excitation light is limiting.</p> <p> </p>

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