scholarly journals Biocompatible Temperature Nanosensors Based on Titanium Dioxide

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 16
Author(s):  
Veronica Zani ◽  
Danilo Pedron ◽  
Roberto Pilot ◽  
Raffaella Signorini
Keyword(s):  
Titanium Dioxide ◽  
Spatial Resolution ◽  
Optical Sensors ◽  
Scattered Light ◽  
Ccd Camera ◽  
Contactless Measurement ◽  
Temperature Detection ◽  
Frequency Position ◽  
Cooled Ccd ◽  
Anti Stokes

The measurement of temperature is of fundamental importance in a huge scale of applications, from nanomedicine, where the early detection of tumorous cells is an essential requirement, to microelectronics and microcircuits. Optical sensors with a micro/nano-spatial resolution can be used for temperature determination within a biological frame. Within this context, Raman spectroscopy is particularly interesting: the inelastic scattering of light has the advantage of a contactless measurement and exploits the temperature-dependence of intensities in the spectrum by observing the intensity ratio of anti-Stokes and Stokes signals. Titanium dioxide can be regarded as a potential optical material for temperature detection in biological samples, thanks to its high biocompatibility, already demonstrated in literature, and to its strong Raman scattering signal. The aim of the present work is the realization of biocompatible optical thermometers, with a sub-micrometric spatial resolution, made of titanium dioxide. Raman measurements have been performed on anatase powder using 514.5, 568.2 and 647.1 nm excitation lines of the CW Ar/Kr ion laser. The laser beam was focalized through a microscope on the sample, kept at defined temperature using a temperature controller. The Stokes and anti-Stokes scattered light was analyzed through a triple monochromator and detected by a liquid nitrogen-cooled CCD camera. Raw data were analyzed with Matlab and Raman spectrum parameters—such as area, intensity, frequency position and width of the peak—were calculated using a Lorentz fitting curve. Preliminary results showed that good reliable temperatures can be obtained.

scholarly journals Contactless Temperature Sensing at the Microscale Based on Titanium Dioxide Raman Thermometry

Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 102
Author(s):  
Veronica Zani ◽  
Danilo Pedron ◽  
Roberto Pilot ◽  
Raffaella Signorini
Keyword(s):  
Titanium Dioxide ◽  
Scattered Light ◽  
Active Material ◽  
Local Temperature ◽  
Visible Range ◽  
Detection Techniques ◽  
Wide Range ◽  
Frequency Position ◽  
Anti Stokes

The determination of local temperature at the nanoscale is a key point to govern physical, chemical and biological processes, strongly influenced by temperature. Since a wide range of applications, from nanomedicine to nano- or micro-electronics, requires a precise determination of the local temperature, significant efforts have to be devoted to nanothermometry. The identification of efficient materials and the implementation of detection techniques are still a hot topic in nanothermometry. Many strategies have been already investigated and applied to real cases, but there is an urgent need to develop new protocols allowing for accurate and sensitive temperature determination. The focus of this work is the investigation of efficient optical thermometers, with potential applications in the biological field. Among the different optical techniques, Raman spectroscopy is currently emerging as a very interesting tool. Its main advantages rely on the possibility of carrying out non-destructive and non-contact measurements with high spatial resolution, reaching even the nanoscale. Temperature variations can be determined by following the changes in intensity, frequency position and width of one or more bands. Concerning the materials, Titanium dioxide has been chosen as Raman active material because of its intense cross-section and its biocompatibility, as already demonstrated in literature. Raman measurements have been performed on commercial anatase powder, with a crystallite dimension of hundreds of nm, using 488.0, 514.5, 568.2 and 647.1 nm excitation lines of the CW Ar+/Kr+ ion laser. The laser beam was focalized through a microscope on the sample, kept at defined temperature using a temperature controller, and the temperature was varied in the range of 283–323 K. The Stokes and anti-Stokes scattered light was analyzed through a triple monochromator and detected by a liquid nitrogen-cooled CCD camera. Raw data have been analyzed with Matlab, and Raman spectrum parameters—such as area, intensity, frequency position and width of the peak—have been calculated using a Lorentz fitting curve. Results obtained, calculating the anti-Stokes/Stokes area ratio, demonstrate that the Raman modes of anatase, in particular the Eg one at 143 cm−1, are excellent candidates for the local temperature detection in the visible range.

scholarly journals Construction and Operation of a dispersive Laser Raman Spectrograph using interference filter

1970 ◽  
Vol 32 (1) ◽  
pp. 121-129
Author(s):  
KM Abedin ◽  
SFU Farhad ◽  
MR Islam ◽  
Aminul I Talukder ◽  
AFMY Haider
Keyword(s):  
Raman Spectra ◽  
Notch Filter ◽  
Ccd Camera ◽  
Interference Filter ◽  
Spectral Lines ◽  
Quantitative Chemical Analysis ◽  
Laser Raman ◽  
Holographic Notch Filter ◽  
Cooled Ccd ◽  
Anti Stokes

A dispersive laser Raman system was designed and constructed using a helium-neon (He-Ne) laser as an excitation source, and an interference filter in the reflection mode for Raleigh filtering instead of the more common holographic notch filter. A commercially available spectrograph equipped with a cooled CCD camera was used to acquire the Raman spectra. The constructed laser Raman spectrograph was found to have excellent performance and sensitivity. Stokes Raman spectra of some common chemicals were acquired by the system, and the wavelengths of spectral lines agreed well with the literature values, within experimental error. The useful spectral range of the system is about 200-4000 cm-1. It was also possible to acquire anti-Stokes Raman spectra of one chemical (CCl4) without much difficulty. We hope to use the system for chemical identification of molecules as well as quantitative chemical analysis. To our knowledge, this is the first laser Raman system constructed in Bangladesh. doi: 10.3329/jbas.v32i1.2451 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 121-129, 2008

Five-Dimensional Microscopy using Widefield-Deconvolution: Practical Considerations and Biological Applications

1996 ◽  
Vol 54 ◽  
pp. 268-269
Author(s):  
W.F. Marshall ◽  
K. Oegema ◽  
J. Nunnari ◽  
A.F. Straight ◽  
D.A. Agard ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
High Speed ◽  
Laser Scanning ◽  
Ccd Camera ◽  
Image Plane ◽  
Time Lapse ◽  
Laser Scanning Confocal Microscopy ◽  
Three Dimensions ◽  
Excitation Light ◽  
Cooled Ccd

The ability to image cells in three dimensions has brought about a revolution in biological microscopy, enabling many questions to be asked which would be inaccessible without this capability. There are currently two major methods of three dimensional microscopy: laser-scanning confocal microscopy and widefield-deconvolution microscopy. The method of widefield-deconvolution uses a cooled CCD to acquire images from a standard widefield microscope, and then computationally removes out of focus blur. Using such a scheme, it is easy to acquire time-lapse 3D images of living cells without killing them, and to do so for multiple wavelengths (using computer-controlled filter wheels). Thus, it is now not only feasible, but routine, to perform five dimensional microscopy (three spatial dimensions, plus time, plus wavelength).Widefield-deconvolution has several advantages over confocal microscopy. The two main advantages are high speed of acquisition (because there is no scanning, a single optical section is acquired at a time by using a cooled CCD camera) and the use of low excitation light levels Excitation intensity can be much lower than in a confocal microscope for three reasons: 1) longer exposures can be taken since the entire 512x512 image plane is acquired in parallel, so that dwell time is not an issue, 2) the higher quantum efficiently of a CCD detect over those typically used in confocal microscopy (although this is expected to change due to advances in confocal detector technology), and 3) because no pinhole is used to reject light, a much larger fraction of the emitted light is collected. Thus we can typically acquire images with thousands of photons per pixel using a mercury lamp, instead of a laser, for illumination. The use of low excitation light is critical for living samples, and also reduces bleaching. The high speed of widefield microscopy is also essential for time-lapse 3D microscopy, since one must acquire images quickly enough to resolve interesting events.

A Time-Resolved Low-Angle Light Scattering Apparatus. Application to Phase Separation Problems in Polymer Systems

2001 ◽  
Vol 66 (6) ◽  
pp. 973-982 ◽  
Author(s):  
Čestmír Koňák ◽  
Jaroslav Holoubek ◽  
Petr Štěpánek
Keyword(s):  
Phase Separation ◽  
Light Scattering ◽  
Signal To Noise Ratio ◽  
Scattered Light ◽  
Ccd Camera ◽  
Time Resolved ◽  
Polymer Systems ◽  
Software Analysis ◽  
Phase Separation Kinetics ◽  
Small Angle Light Scattering

A time-resolved small-angle light scattering apparatus equipped with azimuthal integration by means of a conical lens or software analysis of scattering patterns detected with a CCD camera was developed. Averaging allows a significant reduction of the signal-to-noise ratio of scattered light and makes this technique suitable for investigation of phase separation kinetics. Examples of applications to time evolution of phase separation in concentrated statistical copolymer solutions and dissolution of phase-separated domains in polymer blends are given.

Gamma-ray imaging with an image intensifier and a cooled CCD camera

2001 ◽  
Author(s):  
Naoki Saitoh ◽  
Kenro Kuroki ◽  
Kenji Kurosawa ◽  
Norimitsu Akiba
Keyword(s):  
Gamma Ray ◽  
Image Intensifier ◽  
Ccd Camera ◽  
Gamma Ray Imaging ◽  
Cooled Ccd

scholarly journals A new device to mount portable energy-dispersive X-ray fluorescence spectrometers (p-ED-XRF) for semi-continuous analyses of split (sediment) cores and solid samples

2017 ◽  
Vol 6 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Philipp Hoelzmann ◽  
Torsten Klein ◽  
Frank Kutz ◽  
Brigitta Schütt
Keyword(s):  
Spatial Resolution ◽  
Atlantic Coast ◽  
Sediment Cores ◽  
Ccd Camera ◽  
Energy Dispersive ◽  
Solid Samples ◽  
Industrial Property ◽  
X Ray ◽  
New Device ◽  
Sample Chamber

Abstract. Portable energy-dispersive X-ray fluorescence spectrometers (p-ED-XRF) have become increasingly popular in sedimentary laboratories to quantify the chemical composition of a range of materials such as sediments, soils, solid samples, and artefacts. Here, we introduce a low-cost, clearly arranged unit that functions as a sample chamber (German industrial property rights no. 20 2014 106 048.0) for p-ED-XRF devices to facilitate economic, non-destructive, fast, and semi-continuous analysis of (sediment) cores or other solid samples. The spatial resolution of the measurements is limited to the specifications of the applied p-ED-XRF device – in our case a Thermo Scientific Niton XL3t p-ED-XRF spectrometer with a maximum spatial resolution of 0.3 cm and equipped with a charge-coupled device (CCD) camera to document the measurement spot. We demonstrate the strength of combining p-ED-XRF analyses with this new sample chamber to identify Holocene facies changes (e.g. marine vs. terrestrial sedimentary facies) using a sediment core from an estuarine environment in the context of a geoarchaeological investigation at the Atlantic coast of southern Spain.

scholarly journals Multiscale 2D-SPR Biosensing for Cell Chips

2007 ◽  
Vol 19 (5) ◽  
pp. 519-523 ◽  
Author(s):  
Masayasu Suzuki ◽  
◽  
Toyohiro Ohshima ◽  
Shintaro Hane ◽  
Yasunori Iribe ◽  
...  
Keyword(s):  
Protein A ◽  
Cell Activity ◽  
Ccd Camera ◽  
Pdms Film ◽  
Sensor Film ◽  
Spr Imaging ◽  
Measurement Protocol ◽  
A Cell ◽  
Cooled Ccd ◽  
Imaging Sensor

Evaluating cell activity and functions in different-sized cell chambers requires multiscale sensing. We have been developing multiscale biosensing applied from 10 µm to 1 mm. We measured mouse IgG in micro wells using a high-resolution two-dimensional surface plasmon resonance (SPR) imaging affinity sensor. This sensor uses high refractive optics, a 1X to 7X microscopic lens, and a cooled CCD camera. The micro-well array was prepared with a PDMS film on gold sensor film. Protein A immobilized on sensor film was used for IgG recognition. SPR sensitivity was dramatically decreased with 10 and 8.5 µm microwells. To improve sensor sensitivity, we optimized the sensor’s measurement angle and exposure time, enabling mouse IgG to be detected in wells of 1 mm, 30 µm, and 10 µm using the same 2D-SPR imaging sensor and measurement protocol. These results show the feasibility of multiscale biosensing use in antibody production in a micro well or a cell chamber.

Recent Development of Cone-Beam X-Ray Microtomography at Sunyab

1997 ◽  
Vol 3 (S2) ◽  
pp. 1125-1126
Author(s):  
S.J. Pan ◽  
A. Shih ◽  
W.S. Liou ◽  
M.S. Park ◽  
G. Wang ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Imaging System ◽  
Tomographic Reconstruction ◽  
Ccd Camera ◽  
Test Sample ◽  
Glass Beads ◽  
Cone Beam ◽  
Projection Data ◽  
X Ray ◽  
Cooled Ccd

An experimental X-ray cone-beam microtomographic imaging system utilizing a generalized Feldkamp reconstruction algorithm has been developed in our laboratory. This microtomographic imaging system consists of a conventional dental X-ray source (Aztech 65, Boulder, CO), a sample position and rotation stage, an X-ray scintillation phosphor screen, and a high resolution slow scan cooled CCD camera (Kodak KAF 1400). A generalized Feldkamp cone-beam algorithm was used to perform tomographic reconstruction from cone-beam projection data. This algorithm was developed for various hardware configuration to perform reconstruction of spherical, rod-shaped and plate-like specimen.A test sample consists of 8 glass beads (approx. 800μm in diameter) dispersed in an epoxy-filled #0 gelatin capsule. One hundred X-ray projection images were captured equal angularly (at 3.6 degree spacing) by the cooled CCD camera at a of 1317×967 (17×17mm2) pixels with 12-bit dynamic range. Figure 1 shows a 3D isosurface rendering of the test sample. The eight glass beads and trapped air bubbles (arrows) in the epoxy resin (e) are clearly visible.

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