UV-light microscope: improvements in optical imaging for a secondary ion mass spectrometer

Noriko T. Kita; Peter E. Sobol; James R. Kern; Neal E. Lord; John W. Valley

doi:10.1039/c4ja00349g

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

10.26434/chemrxiv.7098695 ◽

2018 ◽

Author(s):

Elaine A. Kelly ◽

Judith E. Houston ◽

Rachel Evans

Keyword(s):

Real Time ◽

Absorption Spectroscopy ◽

Self Assembly ◽

Uv Light ◽

Wormlike Micelles ◽

Tetraethylene Glycol ◽

Light Illumination ◽

First Time ◽

Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such asdrug delivery and micellar catalysis. Currently, their behaviour in the equilibrium cis-and trans-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C8AzoOC8E4) using small-angle neutron scattering (SANS). We show that the incorporation of in-situUV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C8AzoOC8E4could switch between wormlike micelles (transnative state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked in-situthrough combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

Download Full-text

One-pot low-temperature synthesis of TiO2 nanowire/rGO composites with enhanced photocatalytic activity

RSC Advances ◽

10.1039/c6ra16484f ◽

2016 ◽

Vol 6 (96) ◽

pp. 94092-94097 ◽

Cited By ~ 10

Author(s):

Huan Xing ◽

Wei Wen ◽

Jin-Ming Wu

Keyword(s):

Photocatalytic Activity ◽

Reaction Rate ◽

Uv Light ◽

Reaction Rate Constant ◽

Light Illumination ◽

Low Temperature Synthesis ◽

Temperature Synthesis ◽

One Pot ◽

Tio2 Nanowire

In situ growth of TiO2 nanowires on graphene oxide was achieved at 80 °C in an open atmosphere. The optimized TiO2/rGO hybrid exhibited a reaction rate constant 5.5 times that of TiO2 nanowires towards photodegradations of rhodamine B in water under the UV light illumination.

Download Full-text

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

10.26434/chemrxiv.7098695.v1 ◽

2018 ◽

Author(s):

Elaine A. Kelly ◽

Judith E. Houston ◽

Rachel Evans

Keyword(s):

Real Time ◽

Absorption Spectroscopy ◽

Self Assembly ◽

Uv Light ◽

Wormlike Micelles ◽

Tetraethylene Glycol ◽

Light Illumination ◽

First Time ◽

Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such asdrug delivery and micellar catalysis. Currently, their behaviour in the equilibrium cis-and trans-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C8AzoOC8E4) using small-angle neutron scattering (SANS). We show that the incorporation of in-situUV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C8AzoOC8E4could switch between wormlike micelles (transnative state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked in-situthrough combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

Download Full-text

Multiscale Investigation of Silicon Anode Li Insertion Mechanisms by Time-of-Flight Secondary Ion Mass Spectrometer Imaging Performed on an In Situ Focused Ion Beam Cross Section

Chemistry of Materials ◽

10.1021/acs.chemmater.6b00155 ◽

2016 ◽

Vol 28 (5) ◽

pp. 1566-1573 ◽

Cited By ~ 28

Author(s):

Arnaud Bordes ◽

Eric De Vito ◽

Cédric Haon ◽

Adrien Boulineau ◽

Alexandre Montani ◽

...

Keyword(s):

Cross Section ◽

Mass Spectrometer ◽

Focused Ion Beam ◽

Ion Beam ◽

Time Of Flight ◽

Beam Cross Section ◽

Silicon Anode ◽

Secondary Ion

Download Full-text

In Situ Ion Implantation for Quantitative SIMS Analysis

MRS Proceedings ◽

10.1557/proc-48-273 ◽

1985 ◽

Vol 48 ◽

Cited By ~ 3

Author(s):

Richard T. Lareau ◽

Peter Williams

Keyword(s):

Ion Implantation ◽

Mass Spectrometer ◽

Reference Level ◽

Sims Analysis ◽

Secondary Ion ◽

Quantitative Sims ◽

Better Than ◽

Oxygen Concentrations

ABSTRACTThe primary ion column of a secondary ion mass spectrometer (Cameca IMS 3f) has been used as an ion implanter to prepare calibrated standards, In situ for quantitative SIMS analysis, with an accuracy better than 10%. The technique has been used to determine oxygen concentrations in contaminated TiSi2 films by implanting a reference level of 18O into a portion of the film.

Download Full-text

A facile and efficient preparation of anatase titania nanoparticles in micelle nanoreactors: morphology, structure, and their high photocatalytic activity under UV light illumination

RSC Advances ◽

10.1039/c4ra10018b ◽

2014 ◽

Vol 4 (99) ◽

pp. 56406-56414 ◽

Cited By ~ 25

Author(s):

Reza Abazari ◽

Ali Reza Mahjoub ◽

Soheila Sanati

Keyword(s):

Photocatalytic Activity ◽

Ultraviolet Light ◽

Uv Light ◽

High Photocatalytic Activity ◽

Light Irradiation ◽

Titania Nanoparticles ◽

Light Illumination ◽

Anatase Titania ◽

Ultraviolet Light Irradiation

Comparative photocatalysis degradation of MB dye under ultraviolet light irradiation: (a) without photocatalyst; (b) commercial P25 TiO2 powder; and (c) TiO2 nanoparticles.

Download Full-text

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

10.26434/chemrxiv.12046125 ◽

2020 ◽

Author(s):

Feifei Jia ◽

Jie Wang ◽

Yanyan Zhang ◽

Qun Luo ◽

Luyu Qi ◽

...

Keyword(s):

Mass Spectrometry ◽

Secondary Ion Mass Spectrometry ◽

Single Cells ◽

Time Of Flight ◽

E Coli ◽

Tof Sims ◽

Ion Mass Spectrometry ◽

Chemical Tags ◽

Secondary Ion

In situ visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for in situ visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.

Download Full-text

An Effective SIMS Methodology for GOI Contamination Analysis

ISTFA 2013: Conference Proceedings from the 39th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2013p0427 ◽

2013 ◽

Author(s):

Yanhua Huang ◽

Lei Zhu ◽

Kenny Ong ◽

Hanwei Teo ◽

Younan Hua

Keyword(s):

Oxide Layer ◽

Secondary Ion Mass Spectrometry ◽

Gate Oxide ◽

Sample Surface ◽

Low Energy ◽

Cross Contamination ◽

Common Effect ◽

Sims Analysis ◽

Secondary Ion ◽

Lower Background

Abstract Contamination in the gate oxide layer is the most common effect which cause the gate oxide integrate (GOI) issue. Dynamic Secondary Ion Mass Spectrometry (SIMS) is a mature tool for GOI contamination analysis. During the sample preparation, all metal and IDL layers above poly should be removed because the presence of these layers added complexity for the subsequent SIMS analysis. The normal delayering process is simply carried out by soaking the sample in the HF solution. However, the poly surface is inevitably contaminated by surroundings even though it is already a practice to clean with DI rinse and tape. In this article, TOFSIMS with low energy sputter gun is used to clean the sample surface after the normal delayering process. The residue signals also can be monitored by TOF SIMS during sputtering to confirm the cross contamination is cleared. After that, a much lower background desirable by dynamic SIMS. Thus an accurate depth profile in gate oxide layer can be achieved without the interference from surface.

Download Full-text