Ultrafast laser micro-nano structured superhydrophobic teflon surfaces for enhanced SERS detection via evaporation concentration

2020 ◽  
Vol 9 (1-2) ◽  
pp. 89-100 ◽  
Author(s):  
Xinyu Hu ◽  
Rui Pan ◽  
Mingyong Cai ◽  
Weijian Liu ◽  
Xiao Luo ◽  
...  
Keyword(s):  
Rhodamine 6G ◽  
Optimal Parameter ◽  
Solute Concentration ◽  
Processing Parameter ◽  
Detection Techniques ◽  
Peak Intensity ◽  
Target Analytes ◽  
Sers Detection ◽  
Scanning Path ◽  
Evaporation Concentration

AbstractEvaporation concentration of target analytes dissolved in a water droplet based on superhydrophobic surfaces could be able to break the limits for sensitive trace substance detection techniques (e.g. SERS) and it is promising in the fields such as food safety, eco-pollution, and bioscience. In the present study, polytetrafluoroethylene (PTFE) surfaces were processed by femtosecond laser and the corresponding processing parameter combinations were optimised to obtain surfaces with excellent superhydrophobicity. The optimal parameter combination is: laser power: 6.4 W; scanning spacing: 40 μm; scanning number: 1; and scanning path: 90 degree. For trapping and localising droplets, a tiny square area in the middle of the surface remained unprocessed for each sample. The evaporation and concentration processes of droplets on the optimised surfaces were performed and analyzed, respectively. It is shown that the droplets with targeted solute can successfully collect all solute into the designed trapping areas during evaporation process on our laser fabricated superhydrophobic surface, resulting in detection domains with high solute concentration for SERS characterisation. It is shown that the detected peak intensity of rhodamine 6G with a concentration of 10−6m in SERS characterisation can be obviously enhanced by one or two orders of magnitude on the laser fabricated surfaces compared with that of the unprocessed blank samples.

Ultrasensitive SERS detection of rhodamine 6G and p-nitrophenol based on electrochemically roughened nano-Au film

Talanta ◽  
2020 ◽  
Vol 210 ◽  
pp. 120631 ◽  
Author(s):  
Jiangcai Wang ◽  
Cuicui Qiu ◽  
Xijiao Mu ◽  
Hua Pang ◽  
Xinchun Chen ◽  
...  
Keyword(s):  
Rhodamine 6G ◽  
Au Film ◽  
Sers Detection

scholarly journals Gold Nanostars Bioconjugation for Selective Targeting and SERS Detection of Biofluids

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 665
Author(s):  
Caterina Dallari ◽  
Claudia Capitini ◽  
Martino Calamai ◽  
Andrea Trabocchi ◽  
Francesco Saverio Pavone ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Biological Fluids ◽  
Neuroblastoma Cells ◽  
Neutralizing Antibody ◽  
Surface Enhanced Raman Spectroscopy ◽  
Detection Techniques ◽  
Gold Nanostars ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
Hemagglutinin Protein

Gold nanoparticles (AuNPs) show physicochemical and optical functionalities that are of great interest for spectroscopy-based detection techniques, and especially for surface enhanced Raman spectroscopy (SERS), which is capable of providing detailed information on the molecular content of analysed samples. Moreover, the introduction of different moieties combines the interesting plasmonic properties of the AuNPs with the specific and selective recognition capabilities of the antibodies (Ab) towards antigens. The conjugation of biomolecules to gold nanoparticles (AuNPs) has received considerable attention for analysis of liquid samples and in particular biological fluids (biofluids) in clinical diagnostic and therapeutic field. To date, gold nanostars (AuNSts) are gaining more and more attention as optimal enhancers for SERS signals due to the presence of sharp branches protruding from the core, providing a huge number of “hot spots”. To this end, we focused our attention on the design, optimization, and deep characterization of a bottom up-process for (i) AuNPs increasing stabilization in high ionic strength buffer, (ii) covalent conjugation with antibodies, while (iii) retaining the biofunctionality to specific tag analyte within the biofluids. In this work, a SERS-based substrate was developed for the recognition of a short fragment (HA) of the hemagglutinin protein, which is the major viral antigen inducing a neutralizing antibody response. The activity and specific targeting with high selectivity of the Ab-AuNPs was successfully tested in transfected neuroblastoma cells cultures. Then, SERS capabilities were assessed measuring Raman spectra of HA solution, thus opening interesting perspective for the development of novel versatile highly sensitive biofluids sensors.

SERS detection of trace nitrite ion in aqueous solution based on the nitrosation reaction of rhodamine 6G molecular probe

2014 ◽  
Vol 201 ◽  
pp. 336-342 ◽  
Author(s):  
Yanghe Luo ◽  
Guiqing Wen ◽  
Jinchao Dong ◽  
Qingye Liu ◽  
Aihui Liang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Rhodamine 6G ◽  
Molecular Probe ◽  
Nitrite Ion ◽  
Sers Detection ◽  
Nitrosation Reaction

scholarly journals Tailoring gold and silver colloidal bimetallic nanoalloys towards SERS detection of rhodamine 6G

RSC Advances ◽  
2017 ◽  
Vol 7 (26) ◽  
pp. 15944-15951 ◽  
Author(s):  
A. V. Girão ◽  
P. C. Pinheiro ◽  
M. Ferro ◽  
T. Trindade
Keyword(s):  
Rhodamine 6G ◽  
Bimetallic Alloys ◽  
Gold Silver ◽  
Sers Detection ◽  
Sers Sensing

Nanoparticles of gold, silver and their bimetallic alloys were tailored for SERS sensing towards trace amounts of rhodamine 6G.

Resolution Attainable With the Present Day STEM

1973 ◽  
Vol 31 ◽  
pp. 230-231 ◽  
Author(s):  
J. S. Wall ◽  
J. P. Langmore ◽  
H. Isaacson ◽  
A. V. Crewe
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Incident Beam ◽  
Scanning Transmission Electron Microscope ◽  
Aperture Size ◽  
Magnetic Lens ◽  
Peak Intensity ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Half Angle

The scanning transmission electron microscope (STEM) constructed by the authors employs a field emission gun and a 1.15 mm focal length magnetic lens to produce a probe on the specimen. The aperture size is chosen to allow one wavelength of spherical aberration at the edge of the objective aperture. Under these conditions the profile of the focused spot is expected to be similar to an Airy intensity distribution with the first zero at the same point but with a peak intensity 80 per cent of that which would be obtained If the lens had no aberration. This condition is attained when the half angle that the incident beam subtends at the specimen, 𝛂 = (4𝛌/Cs)¼

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Analytical Electron Microscopy of Surface-Modified Ceramics

1985 ◽  
Vol 43 ◽  
pp. 276-279
Author(s):  
P. S. Sklad
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Theoretical Models ◽  
Ceramic Materials ◽  
Solute Concentration ◽  
Second Phase ◽  
Analytical Electron ◽  
Implantation Techniques ◽  
Lattice Damage ◽  
Surface Modified

Over the past several years, it has become increasingly evident that materials for proposed advanced energy systems will be required to operate at high temperatures and in aggressive environments. These constraints make structural ceramics attractive materials for these systems. However it is well known that the condition of the specimen surface of ceramic materials is often critical in controlling properties such as fracture toughness, oxidation resistance, and wear resistance. Ion implantation techniques offer the potential of overcoming some of the surface related limitations.While the effects of implantation on surface sensitive properties may be measured indpendently, it is important to understand the microstructural evolution leading to these changes. Analytical electron microscopy provides a useful tool for characterizing the microstructures produced in terms of solute concentration profiles, second phase formation, lattice damage, crystallinity of the implanted layer, and annealing behavior. Such analyses allow correlations to be made with theoretical models, property measurements, and results of complimentary techniques.

Sign in / Sign up

Export Citation Format

Share Document