scholarly journals A New FRET-Based Sensitive DNA Sensor for Medical Diagnostics using PNA Probe and Water-Soluble Blue Light Emitting Polymer

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Nidhi Mathur ◽  
Anamika Aneja ◽  
P. K. Bhatnagar ◽  
P. C. Mathur
Keyword(s):  
Dna Sequence ◽  
Low Cost ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Medical Diagnostics ◽  
Water Soluble ◽  
Complementary Sequence ◽  
Sequence Detection ◽  
Light Emitting ◽  
Dna Sequence Detection

A reliable, fast, and low-cost biosensor for medical diagnostics using DNA sequence detection has been developed and tested for the detection of the bacterium “Bacillus anthracis.” In this sensor, Poly [9,9-di (6,6′- N,N′trimethylammonium) hexylfluorenyl-2, 7-diyl)-alt-co- (1,4-phenylene)] dibromide salt (PFP) has been taken as cationic conjugated polymer (CCP) and PNA attached with fluorescein dye (PNAC∗) as a probe. The basic principle of this sensor is that when aPNAC∗probe is hybridized with a single strand DNA (ssDNA) having complementary sequence, Forster resonance energy transfer (FRET) may take place from PFP to thePNAC∗/DNA complex. If the FRET is efficient, the photoluminescence from the PFP will be highly quenched and that fromPNAC∗will be enhanced. On the other hand, if the DNA sequence is noncomplementary to PNA, FRET will not occur.

scholarly journals Graphene Oxide and Fluorescent Aptamer Based Novel Biosensor for Detection of 25-hydroxyvitamin D3

2021 ◽  
Author(s):  
Ritika Gupta ◽  
Sunaina Kaul ◽  
Vishal Singh ◽  
Sandeep Kumar ◽  
Nitin Kumar Singhal
Keyword(s):  
Vitamin D ◽  
Graphene Oxide ◽  
Limit Of Detection ◽  
Low Cost ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Detection Methods ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Sensitive Sensor

Abstract For maintaining the healthy metabolic status, vitamin D is a beneficial metabolite stored majorly in its pre-activated form, 25-hydroxyvitamin D3 (25(OH)D3). Due to its important role in bone strengthening, the study was planned to quantify 25(OH)D3 levels in our blood. Quantification techniques for 25(OH)D3 are costly thus requiring a need for a low cost, and sensitive detection methods. In this work, an economic, and sensitive sensor for the detection of 25(OH)D3 was developed using aptamer and graphene oxide (GO). Aptamer is an oligonucleotide, sensitive towards its target, whereas, GO with 2D nanosheets provides excellent quenching surface. Aptamer labeled with fluorescein (5’, 6-FAM) is adsorbed by π -π interaction on the GO sheets leading to quenching of the fluorescence due to Förster resonance energy transfer (FRET). However, in the presence of 25(OH)D3, a major portion of aptamer fluorescence remains unaltered, due to its association with 25(OH)D3. However, in the absence, aptamer fluorescence gets fully quenched. Fluorescence intensity quenching was monitored using fluorescence spectrophotometer and agarose gel based system. The limit of detection of 25(OH)D3 by this method was found to be 0.15 µg/mL. Therefore, this method could come up as a new sensing method in the field of vitamin D detection.

Turning on a high-rate-capability fluorescence resonance energy transfer in quantum dots-molecule system via high pressure

2021 ◽  
Author(s):  
Bo Li ◽  
Bifa Cao ◽  
Qiao Zhou ◽  
You Li ◽  
Yongjun Bao ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Rate Capability ◽  
Resonance Energy ◽  
High Rate ◽  
Optical Biosensing ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Fluorescence Resonance

Turning on Fluorescence Resonance Energy Transfer (FRET) based on Quantum dot (QD)-molecule system plays crucial roles in developing photovoltaic solar cells, optical biosensing schemes and light-emitting devices. The present achievement...

Achieving High Efficiency and Pure Blue Color in Hyperfluorescence Organic Light Emitting Diodes using Organo-Boron Based Emitters

2021 ◽  
Author(s):  
Kenkera Naveen ◽  
Hyuna Lee ◽  
Ramanaskanda Braveenth ◽  
Durai Karthik ◽  
Ki Yang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Blue Color ◽  
Orientation Factor ◽  
Light Emitting ◽  
Organic Light

Abstract In the field of organic light emitting diodes (OLEDs), organo-boron based thermally activated delayed fluorescence (TADF) emitters have reached great achievement. However, it is still challenging to achieve pure blue color (CIE y < 0.20) along with high efficiencies. To overcome these hurdles, hyperfluorescence (HF) suggest a key strategy in future OLED applications. Here, we report two TADF materials, pMDBA-DI and mMDBA-DI. Further, a pure blue multi resonance type tert-butyl substituted fluorescence emitter, t-Bu-ν-DABNA was also synthesized. Among our synthesized TADF materials based pure blue HF devices, mMDBA-DI as TADF sensitized host with t-Bu-ν-DABNA fluorescence emitter exhibited a high external quantum efficiency of 40.7% (Lambertian assumption) along with narrow emission with full width at half maximum of 19 nm (CIE y = 0.15). Moreover, we analyzed that such high device efficiency is mainly attributed to the high orientation factor, enhanced photoluminescence quantum yield, and a good TADF characteristic of t-Bu-ν-DABNA with high Förster resonance energy transfer.

scholarly journals Peptide-coated palladium nanoparticle for highly sensitive bioanalysis of trypsin in human urine samples

2018 ◽  
Vol 8 ◽  
pp. 184798041882039 ◽  
Author(s):  
Guohua Zhou ◽  
Huimin Jiang ◽  
Yanfang Zhou ◽  
Peilian Liu ◽  
Yongmei Jia ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Palladium Nanoparticles ◽  
Limit Of Detection ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Water Soluble ◽  
Urine Samples ◽  
Fluorescence Resonance ◽  
Functional Peptide

In recent years, palladium nanoparticles have been proved as energy acceptor candidates in fluorescence resonance energy transfer-based sensors for analytical and biological purposes. In this article, peptide-coated palladium nanoparticles were prepared using a simple one-step preparation method. The peptide Cys-Ala-Leu-Asn-Asn was used as a ligand, whereas hydrazine hydrate was used as a reductant to obtain water-soluble and stable peptide-coated palladium nanoparticles. Additionally, peptide-coated palladium nanoparticles were functionalized by adding the functional peptide CALNNGGARK(FITC) in combination with Cys-Ala-Leu-Asn-Asn during the preparation process. The prepared functionalized peptide-coated palladium nanoparticles were used for trypsin detection based on the fluorescence resonance energy transfer approach. Under optimized conditions, the proposed method can be used for the detection of trypsin concentrations in the range of approximately 0.2–8-μg/mL with a limit of detection of 0.18-μg/mL. The functionalized peptide-coated palladium nanoparticles were successfully applied for the detection of trypsin in urine samples. Our findings also indicated that peptide-coated palladium nanoparticles can highly quench fluorophores and are suitable for the manufacture of off–on state fluorescent sensors. We anticipated that the peptide-coated palladium nanoparticles proposed in this article will have great potential for the detection of trypsin in urine and other analytical, biological, and clinical applications.

scholarly journals Pencil–paper on-skin electronics

2020 ◽  
Vol 117 (31) ◽  
pp. 18292-18301 ◽  
Author(s):  
Yadong Xu ◽  
Ganggang Zhao ◽  
Liang Zhu ◽  
Qihui Fei ◽  
Zhe Zhang ◽  
...  
Keyword(s):  
Uric Acid ◽  
Low Cost ◽  
Three Dimensional ◽  
Water Soluble ◽  
Transdermal Drug Delivery System ◽  
Gradient Distribution ◽  
Light Emitting ◽  
Energy Harvesters ◽  
Self Powered ◽  
Reconfigurable Assembly

Pencils and papers are ubiquitous in our society and have been widely used for writing and drawing, because they are easy to use, low-cost, widely accessible, and disposable. However, their applications in emerging skin-interfaced health monitoring and interventions are still not well explored. Herein, we report a variety of pencil–paper-based on-skin electronic devices, including biophysical (temperature, biopotential) sensors, sweat biochemical (pH, uric acid, glucose) sensors, thermal stimulators, and humidity energy harvesters. Among these devices, pencil-drawn graphite patterns (or combined with other compounds) serve as conductive traces and sensing electrodes, and office-copy papers work as flexible supporting substrates. The enabled devices can perform real-time, continuous, and high-fidelity monitoring of a range of vital biophysical and biochemical signals from human bodies, including skin temperatures, electrocardiograms, electromyograms, alpha, beta, and theta rhythms, instantaneous heart rates, respiratory rates, and sweat pH, uric acid, and glucose, as well as deliver programmed thermal stimulations. Notably, the qualities of recorded signals are comparable to those measured with conventional methods. Moreover, humidity energy harvesters are prepared by creating a gradient distribution of oxygen-containing groups on office-copy papers between pencil-drawn electrodes. One single-unit device (0.87 cm2) can generate a sustained voltage of up to 480 mV for over 2 h from ambient humidity. Furthermore, a self-powered on-skin iontophoretic transdermal drug-delivery system is developed as an on-skin chemical intervention example. In addition, pencil–paper-based antennas, two-dimensional (2D) and three-dimensional (3D) circuits with light-emitting diodes (LEDs) and batteries, reconfigurable assembly and biodegradable electronics (based on water-soluble papers) are explored.

scholarly journals Ratiometric pH Sensing and Imaging in Living Cells with Dual-Emission Semiconductor Polymer Dots

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2923
Author(s):  
Piaopiao Chen ◽  
Iqra Ilyas ◽  
Su He ◽  
Yichen Xing ◽  
Zhigang Jin ◽  
...  
Keyword(s):  
Fluorescent Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Fluorescein Isothiocyanate ◽  
Water Soluble ◽  
Ph Sensing ◽  
Dual Emission ◽  
Polymer Dots ◽  
Ratiometric Ph Sensing

Polymer dots (Pdots) represent newly developed semiconductor polymer nanoparticles and exhibit excellent characteristics as fluorescent probes. To improve the sensitivity and biocompatibility of Pdots ratiometric pH biosensors, we synthesized 3 types of water-soluble Pdots: Pdots-PF, Pdots-PP, and Pdots-PPF by different combinations of fluorescent dyes poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO), poly[(9,9-dioctyl-fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1′,3}-thiadazole)] (PFBT), and fluorescein isothiocyanate (FITC). We found that Pdots-PPF exhibits optimal performance on pH sensing. PFO and FITC in Pdots-PPF produce pH-insensitive (λ = 439 nm) and pH-sensitive (λ = 517 nm) fluorescence respectively upon a single excitation at 380 nm wavelength, which enables Pdots-PPF ratiometric pH sensing ability. Förster resonance energy transfer (FRET) together with the use of PFBT amplify the FITC signal, which enables Pdots-PPF robust sensitivity to pH. The emission intensity ratio (I517/I439) of Pdots-PPF changes linearly as a function of pH within the range of pH 3.0 to 8.0. Pdots-PPF also possesses desirable reversibility and stability in pH measurement. More importantly, Pdots-PPF was successfully used for cell imaging in Hela cells, exhibiting effective cellular uptake and low cytotoxicity. Our study suggests the promising potential of Pdots-PPF as an in vivo biomarker.

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