Enhanced DNA detection using a multiple pulse pumping scheme with time-gating (MPPTG)

The Analyst ◽  
2018 ◽  
Vol 143 (12) ◽  
pp. 2819-2827 ◽  
Author(s):  
Joseph D. Kimball ◽  
Badri Maliwal ◽  
Sangram L. Raut ◽  
Hung Doan ◽  
Zhangatay Nurekeyev ◽  
...  

Fluorescence signal enhancement induced by the binding of intercalators to DNA has been broadly utilized in various DNA detection methods.

2015 ◽  
Vol 88 (5) ◽  
pp. 888-894 ◽  
Author(s):  
Allex Jardim da Fonseca ◽  
Renata Silva Galvão ◽  
Angelica Espinosa Miranda ◽  
Luiz Carlos de Lima Ferreira ◽  
Zigui Chen

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5110
Author(s):  
Mari Okada ◽  
Hiroka Sugai ◽  
Shunsuke Tomita ◽  
Ryoji Kurita

Recently, pattern-recognition-based protein sensing has received considerable attention because it offers unique opportunities that complement more conventional antibody-based detection methods. Here, we report a multichannel pattern-recognition-based sensor using a set of fluorophore-conjugated single-stranded DNAs (ssDNAs), which can detect various proteins. Three different fluorophore-conjugated ssDNAs were placed into a single microplate well together with a target protein, and the generated optical response pattern that corresponds to each environment-sensitive fluorophore was read via multiple detection channels. Multivariate analysis of the resulting optical response patterns allowed an accurate detection of eight different proteases, indicating that fluorescence signal acquisition from a single compartment containing a mixture of ssDNAs is an effective strategy for the characterization of the target proteins. Additionally, the sensor could identify proteins, which are potential targets for disease diagnosis, in a protease and inhibitor mixture of different composition ratios. As our sensor benefits from simple construction and measurement procedures, and uses accessible materials, it offers a rapid and simple platform for the detection of proteins.


2020 ◽  
Vol 54 (4) ◽  
pp. 324-335
Author(s):  
Stavroula Michou ◽  
Ana Raquel Benetti ◽  
Christoph Vannahme ◽  
Pétur Gordon Hermannsson ◽  
Azam Bakhshandeh ◽  
...  

<b><i>Objectives:</i></b> To develop an automated fluorescence-based caries scoring system for an intraoral scanner and to<i></i>test the performance of the system compared to state-of-the-art methods. <b><i>Methods:</i></b> Seventy-three permanent posterior teeth were scanned with a three-dimensional (3D) intraoral scanner prototype which emitted light at 415 nm. An overlay representing the fluorescence signal from the tissue was mapped onto 3D models of the teeth. Multiple examination sites (<i>n</i> = 139) on the occlusal surfaces were chosen, and their red and green fluorescence signal components were extracted. These components were used to calculate 4 mathematical functions upon which a caries scoring system for the scanner prototype could be based. Visual-tactile (International Caries Detection and Assessment System, ICDAS), radiographic (ICDAS), and histological assessments were conducted on the same examination sites. <b><i>Results:</i></b> Most index tests showed significant correlation with histology. The strongest correlation was observed for the visual-tactile examination (<i>r</i><sub>s</sub> = 0.80) followed by the scanner supported by the caries classification function that quantifies the overall fluorescence compared to sound surfaces (<i>r</i><sub>s</sub> = 0.78). Additionally, this function resulted in the highest intra-examiner reliability (κ = 0.964), and the highest sum of sensitivity (SE) and specificity (SP) (sum SE-SP: 1.60–1.84) at the 2 histological levels where the comparison with visual-tactile assessment was possible (κ = 0.886, sum SE-SP = 1.57–1.81) and at the 3 out of 4 histological levels where the comparison with radiographic assessment was possible (κ = 0.911, sum SE-SP = 1.37–1.78); the only exception was for the lesions in the outer third of dentin, where the radiographic assessment showed the highest sum SE-SP (1.78). <b><i>Conclusion:</i></b> A fluorescence-based caries scoring system was developed for the intraoral scanner showing promising performance compared to state-of-the-art caries detection methods. The intraoral scanner accompanied by an automated caries scoring system may improve objective caries detection and increase the efficiency and effectiveness of oral examinations. Furthermore, this device has the potential to support reliable monitoring of early caries lesions.


1983 ◽  
Vol 2 (2) ◽  
pp. 37-51 ◽  
Author(s):  
Warren S. Warren ◽  
Ahmed H. Zewail

In this paper we describe a new technique for the generation of multiple pulse phase coherent sequences in optical spectroscopy. The technique is an extension of the acousto-optic modulation and fluorescence detection methods developed for optical transitions by Zewail and Orlowski (Zewail et al., Chem. Phys. Lett.48, 256 (1977); Orlowski et al., Chem. Phys. Lett.54, 197 (1978)). Application of these multiple pulse trains (of different phases) to optical transitions of two-level and multilevel systems is demonstrated experimentally. It is shown that they can be used to (i) suppress spontaneous emission background, (ii) enhance coherent transients such as photon echoes, (iii) measure additional relaxation parameters in systems with complex rotational-vibrational levels, and (iv) enhance the effective laser bandwidths through composite pulse trains, as demonstrated on I2 gas. Finally, the potential of this development is extended to the possibility of observing selective multiquantum excitation in molecules.


Nanoscale ◽  
2015 ◽  
Vol 7 (4) ◽  
pp. 1424-1436 ◽  
Author(s):  
Manpreet Singh ◽  
Ruibin Jiang ◽  
Heidi Coia ◽  
Daniel S. Choi ◽  
Anginelle Alabanza ◽  
...  

We have carried out a combined experimental and simulation study identifying the key physical and optical parameters affecting the biomolecular fluorescence signal enhancement measured on ZnO NRs.


1983 ◽  
Vol 55 (14) ◽  
pp. 2464-2466 ◽  
Author(s):  
A. J. M. Vermorken ◽  
C. M. A. A. Goos ◽  
M. W. A. C. Hukkelhoven ◽  
M. Coelen

2011 ◽  
Vol 11 (7) ◽  
pp. 6203-6207 ◽  
Author(s):  
Hyun Choi ◽  
Insung S. Choi ◽  
Gil Sun Lee ◽  
Dong June Ahn

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 227
Author(s):  
Damiano Verardo ◽  
Leena Liljedahl ◽  
Corinna Richter ◽  
Björn Agnarsson ◽  
Ulrika Axelsson ◽  
...  

Fluorescence-based detection assays play an essential role in the life sciences and medicine. To offer better detection sensitivity and lower limits of detection (LOD), there is a growing need for novel platforms with an improved readout capacity. In this context, substrates containing semiconductor nanowires may offer significant advantages, due to their proven light-emission enhancing, waveguiding properties, and increased surface area. To demonstrate and evaluate the potential of such nanowires in the context of diagnostic assays, we have in this work adopted a well-established single-chain fragment antibody-based assay, based on a protocol previously designed for biomarker detection using planar microarrays, to freestanding, SiO2-coated gallium phosphide nanowires. The assay was used for the detection of protein biomarkers in highly complex human serum at high dilution. The signal quality was quantified and compared with results obtained on conventional flat silicon and plastic substrates used in the established microarray applications. Our results show that using the nanowire-sensor platform in combination with conventional readout methods, improves the signal intensity, contrast, and signal-to-noise by more than one order of magnitude compared to flat surfaces. The results confirm the potential of lightguiding nanowires for signal enhancement and their capacity to improve the LOD of standard diagnostic assays.


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