scholarly journals The Luminescence of 1,8-Diazafluoren-9-One/Titanium Dioxide Composite Thin Films for Optical Application

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3014
Author(s):  
Aneta Lewkowicz ◽  
Robert Bogdanowicz ◽  
Piotr Bojarski ◽  
Mattia Pierpaoli ◽  
Ignacy Gryczyński ◽  
...  
Keyword(s):  
Amino Acids ◽  
Titanium Dioxide ◽  
Detection Methods ◽  
Label Free ◽  
Force Microscopy ◽  
Transparent Substrate ◽  
Atomic Force ◽  
Potential Marker ◽  
Fluorescent Products ◽  
Microscopic Techniques

The investigation of innovative label-free α-amino acids detection methods represents a crucial step for the early diagnosis of several diseases. While 1,8-diazafluoren-9-one (DFO) is known in forensic application because of the fluorescent products by reacting with the amino acids present in the papillary exudate, its application for diagnostic purposes has not been fully investigated. The stabilization of DFO over a transparent substrate allows its complexation with biomolecules for the detection of α-amino acids. In this study, DFO was immobilized into a titanium dioxide (TiO2) matrix for the fluorescence detection of glycine, as a target α-amino acid (a potential marker of the urogenital tract cancers). The DFO/TiO2 composite was characterized by atomic force microscopy, spectroscopic ellipsometry, fluorescence spectroscopy and fluorescence microscopy. The performed fluorescent studies indicate spectacular formation of aggregates at higher concentration. The measurements performed using various fluorescence and microscopic techniques together with the suitable analysis show that the aggregates are able to emit short-lived fluorescence.

scholarly journals 3D phonon microscopy with sub-micron axial-resolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard J. Smith ◽  
Fernando Pérez-Cota ◽  
Leonel Marques ◽  
Matt Clark
Keyword(s):  
Signal To Noise Ratio ◽  
Single Cells ◽  
Optical Resolution ◽  
Acquisition Time ◽  
Label Free ◽  
Axial Resolution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Accuracy And Precision ◽  
Good Agreement

AbstractBrillouin light scattering (BLS) is an emerging method for cell imaging and characterisation. It allows elasticity-related contrast, optical resolution and label-free operation. Phonon microscopy detects BLS from laser generated coherent phonon fields to offer an attractive route for imaging since, at GHz frequencies, the phonon wavelength is sub-optical. Using phonon fields to image single cells is challenging as the signal to noise ratio and acquisition time are often poor. However, recent advances in the instrumentation have enabled imaging of fixed and living cells. This work presents the first experimental characterisation of phonon-based axial resolution provided by the response to a sharp edge. The obtained axial resolution is up to 10 times higher than that of the optical system used to take the measurements. Validation of the results are obtained with various polymer objects, which are in good agreement with those obtained using atomic force microscopy. Edge localisation, and hence profilometry, of a phantom boundary is measured with accuracy and precision of approximately 60 nm and 100 nm respectively. Finally, 3D imaging of fixed cells in culture medium is demonstrated.

Comparative Study of Nanoscale Surface Structures of Calcite Microcrystals Using FE-SEM, AFM, and TEM

2006 ◽  
Vol 12 (4) ◽  
pp. 302-310 ◽  
Author(s):  
Yung-Ching Chien ◽  
Alfonso Mucci ◽  
Jeanne Paquette ◽  
S. Kelly Sears ◽  
Hojatollah Vali
Keyword(s):  
Electron Microscopy ◽  
Three Dimensional ◽  
Quantitative Information ◽  
Surface Structures ◽  
Surface Features ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Micrometer Size ◽  
Microscopic Techniques

The bulk morphology and surface features that developed upon precipitation on micrometer-size calcite powders and millimeter-size cleavage fragments were imaged by three different microscopic techniques: field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) of Pt-C replicas, and atomic force microscopy (AFM). Each technique can resolve some nanoscale surface features, but they offer different ranges of magnification and dimensional resolutions. Because sample preparation and imaging is not constrained by crystal orientation, FE-SEM and TEM of Pt-C replicas are best suited to image the overall morphology of microcrystals. However, owing to the decoration effect of Pt-C on the crystal faces, TEM of Pt-C replicas is superior at resolving nanoscale surface structures, including the development of new faces and the different microtopography among nonequivalent faces in microcrystals, which cannot be revealed by FE-SEM. In conjunction with SEM, Pt-C replica provides the evidence that crystals grow in diverse and face-specific modes. The TEM imaging of Pt-C replicas has nanoscale resolution comparable to AFM. AFM yielded quantitative information (e.g., crystallographic orientation and height of steps) of microtopographic features. In contrast to Pt-C replicas and SEM providing three-dimensional images of the crystals, AFM can only image one individual cleavage or flat surface at a time.

scholarly journals Label-free identification and characterization of living human primary and secondary tumour cells

The Analyst ◽  
2015 ◽  
Vol 140 (15) ◽  
pp. 5162-5168 ◽  
Author(s):  
Dimitrios Tsikritsis ◽  
Susanna Richmond ◽  
Patrick Stewart ◽  
Alistair Elfick ◽  
Andrew Downes
Keyword(s):  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
Tumour Cells ◽  
Label Free ◽  
Force Microscopy ◽  
Atomic Force ◽  
Secondary Tumour ◽  
Identification And Characterization

Primary and secondary tumour cells exhibit biochemical differences (with Raman spectroscopy and imaging), and mechanical differences (with atomic force microscopy).

Label-free quantification of activated NF-κB in biological samples by atomic force microscopy

2010 ◽  
Vol 25 (11) ◽  
pp. 2490-2496 ◽  
Author(s):  
Michele Menotta ◽  
Rita Crinelli ◽  
Elisa Carloni ◽  
Marzia Bianchi ◽  
Elisa Giacomini ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Biological Samples ◽  
Label Free ◽  
Force Microscopy ◽  
Label Free Quantification ◽  
Atomic Force ◽  
Free Quantification
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