scholarly journals Multimodal CTC detection using stem cell antigen-specific immunosilica particles and immunofluorescent quantum dots

2022 ◽  
Vol 14 (1) ◽  
Author(s):  
Jeladhara Sobhanan ◽  
Yuta Takano ◽  
Sakiko Sugino ◽  
Eri Hirata ◽  
Shohei Yamamura ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Stem Cell ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Single Photon ◽  
Photon Counting ◽  
Cell Detection ◽  
Blood Samples ◽  
Single Photon Counting ◽  
Cell Antigen

AbstractAmid the COVID-19 pandemic, cancer continues to be the most devastating disease worldwide. Liquid biopsy of circulating tumor cells (CTCs) has recently become a painless and noninvasive tool for obtaining carcinoma cell samples for molecular profiling. Here, we report efficient detection and collection of cancer cells in blood samples by combining stem cell antigen (CD44)-specific immunosilica particles and immunofluorescent quantum dots with spectrally and temporally resolved single-photon counting. We accurately detect 1–10 cells among 100 cancer cells of the breast, lungs, or cervix in 1 mL blood samples. In addition, the bright and narrowband emission of CdSe/ZnS quantum dots enables temporally and spectrally resolved photon counting for multiplexed cancer cell detection. The cancer cell-specific and large immunosilica particles helped us collect the specific cells. We validate the detection efficiency and multimodality of this strategy by time-stamped and energy-dispersed single-photon counting of orange- and red-emitting quantum dots and green-fluorescing nuclei stained with Syto-13/25 dye. Thus, the present work highlights the prospects of multimodal CTC detection for noninvasive cancer screening and postsurgical or therapeutic follow-up.

scholarly journals Control of the direction of energy transfer in associates of colloidal quantum dots Ag2S/TGA and dye molecules

2018 ◽  
Vol 190 ◽  
pp. 04015
Author(s):  
Oleg V. Ovchinnikov ◽  
Mikhail S. Smirnov ◽  
Irina G. Grevtseva ◽  
Tamara S. Kondratenko ◽  
Aleksey S. Perepelitsa
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Luminescence Band ◽  
Single Photon ◽  
Photon Counting ◽  
Luminescence Spectroscopy ◽  
Simultaneous Reduction ◽  
Single Photon Counting ◽  
Transmission Electron ◽  
Average Size

The possibilities for changing the direction of energy transfer in hybrid associates of colloidal Ag2S quantum dots (QDs) and thionine molecules are analyzed. The studies were performed by transmission electron microscopy, absorption and luminescence spectroscopy, PL decay study (time correlated single photon counting). An increasing of the average QDs size from 1.8 nm to 5.5 nm, and also a shift of the luminescence band from 630 nm to 950 nm, were found at using of TGA molecules and sodium sulfide as a sulfur precursor. Hybrid association of QDs (1.8 nm) with TH+ molecules leads to quenching of QDs luminescence with a simultaneous reduction of the luminescence lifetime from 13.7 to 6.5 ns. An association of QDs with a luminescence band maximum of 950 nm with TH+ molecules leads to quenching of TH+ luminescence and a reduction in its lifetime of luminescence from 0.43 to 0.3 ns. It was concluded that the reduction of lifetime of luminescence caused by the resonant nonradiative energy transfer between the components of the associates. An increasing in the average size of QDs leads to a change in the direction of energy transfer between the components of the associates.

scholarly journals Detection of VAR2CSA-Captured Colorectal Cancer Cells from Blood Samples by Real-Time Reverse Transcription PCR

Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 5881
Author(s):  
Sara R. Bang-Christensen ◽  
Viatcheslav Katerov ◽  
Amalie M. Jørgensen ◽  
Tobias Gustavsson ◽  
Swati Choudhary ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
White Blood Cells ◽  
Amplification Efficiency ◽  
Cell Detection ◽  
Invasive Approach ◽  
Blood Samples ◽  
Highly Sensitive

Analysis of circulating tumor cells (CTCs) from blood samples provides a non-invasive approach for early cancer detection. However, the rarity of CTCs makes it challenging to establish assays with the required sensitivity and specificity. We combine a highly sensitive CTC capture assay exploiting the cancer cell binding recombinant malaria VAR2CSA protein (rVAR2) with the detection of colon-related mRNA transcripts (USH1C and CKMT1A). Cancer cell transcripts are detected by RT-qPCR using proprietary Target Enrichment Long-probe Quantitative Amplified Signal (TELQAS) technology. We validate each step of the workflow using colorectal cancer (CRC) cell lines spiked into blood and compare this with antibody-based cell detection. USH1C and CKMT1A are expressed in healthy colon tissue and CRC cell lines, while only low-level expression can be detected in healthy white blood cells (WBCs). The qPCR reaction shows a near-perfect amplification efficiency for all primer targets with minimal interference of WBC cDNA. Spike-in of 10 cancer cells in 3 mL blood can be detected and statistically separated from control blood using the RT-qPCR assay after rVAR2 capture (p < 0.01 for both primer targets, Mann-Whitney test). Our results provide a validated workflow for highly sensitive detection of magnetically enriched cancer cells.

scholarly journals Фотолюминесценция с временным разрешением наноструктур InGaAs различной квантовой размерности

2019 ◽  
Vol 53 (11) ◽  
pp. 1520
Author(s):  
А.М. Надточий ◽  
С.А. Минтаиров ◽  
Н.А. Калюжный ◽  
М.В. Максимов ◽  
Д.А. Санников ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Well ◽  
Single Photon ◽  
Photon Counting ◽  
Dimensional Structure ◽  
Time Resolved ◽  
Single Photon Counting ◽  
Gaas Substrates ◽  
Photoluminescence Lifetime ◽  
Time Resolved Photoluminescence

By using time-correlated single-photon counting time-resolved photoluminescence of quantum-sized heterostructures of different dimensionality was investigated. InGaAs quantum dots, quantum well, and transitionally-dimensional structure — quantum well-dots were grown on GaAs substrates. It was observed, that photoluminescence decay strongly depends on structure dimensionality resulting in decay value of 6,7, and more than 20 ns for quantum dots, well-dots and well, respectively. As we believe localization centers in heterostructures may be responsible for such shortening of photoluminescence lifetime.

scholarly journals Time-Tagged Single Photon Counting Examination of Rotation of Receptor-Bound Quantum Dots

2019 ◽  
Vol 116 (3) ◽  
pp. 138a
Author(s):  
Dongmei Zhang ◽  
Jason Pace ◽  
Deborah A. Roess ◽  
B. George Barisas
Keyword(s):  
Quantum Dots ◽  
Single Photon ◽  
Photon Counting ◽  
Single Photon Counting

Single Point PICA Probing with an Avalanche Photo-Diode

2001 ◽  
Author(s):  
Mike Bruce ◽  
Rama R. Goruganthu ◽  
Shawn McBride ◽  
David Bethke ◽  
J.M. Chin
Keyword(s):  
Single Photon ◽  
Single Point ◽  
Photon Counting ◽  
Ring Oscillator ◽  
Time Resolved ◽  
Single Photon Counting ◽  
Photo Diode ◽  
Avalanche Photo Diode ◽  
Photo Multiplier Tube ◽  
Channel Plate

Abstract For time resolved hot carrier emission from the backside, an alternate approach is demonstrated termed single point PICA. The single point approach records time resolved emission from an individual transistor using time-correlated-single-photon counting and an avalanche photo-diode. The avalanche photo-diode has a much higher quantum efficiency than micro-channel plate photo-multiplier tube based imaging cameras typically used in earlier approaches. The basic system is described and demonstrated from the backside on a ring oscillator circuit.

scholarly journals UVscope and its application aboard the ASTRI-Horn telescope

2021 ◽  
Author(s):  
Maria Concetta Maccarone ◽  
Giovanni La Rosa ◽  
Osvaldo Catalano ◽  
Salvo Giarrusso ◽  
Alberto Segreto ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Single Photon ◽  
Photon Counting ◽  
Light Flux ◽  
Cosmic Ray ◽  
High Energy ◽  
Wide Field ◽  
High Energy Astrophysics ◽  
Single Photon Counting ◽  
Photon Counting Mode

AbstractUVscope is an instrument, based on a multi-pixel photon detector, developed to support experimental activities for high-energy astrophysics and cosmic ray research. The instrument, working in single photon counting mode, is designed to directly measure light flux in the wavelengths range 300-650 nm. The instrument can be used in a wide field of applications where the knowledge of the nocturnal environmental luminosity is required. Currently, one UVscope instrument is allocated onto the external structure of the ASTRI-Horn Cherenkov telescope devoted to the gamma-ray astronomy at very high energies. Being co-aligned with the ASTRI-Horn camera axis, UVscope can measure the diffuse emission of the night sky background simultaneously with the ASTRI-Horn camera, without any interference with the main telescope data taking procedures. UVscope is properly calibrated and it is used as an independent reference instrument for test and diagnostic of the novel ASTRI-Horn telescope.

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