214 research outputs found
Subnanomolar detection of tuberculosis biomarker MPT64 in sandwich sers immunoassay on novel low -cost substrate
The use of SERS for detection, analysis and imaging has attracted great interest in the
past decade owing to its high sensitivity and molecular fingerprint specificity. There is an increasing
interest in scientific community to SERS as it becomes a versatile method for early medical diagnostics
and reliable detection of major health threats to humans (e.g. cancer, tuberculosis, etc) and animals [1].
The key component of our SERS-based immunoassay include:1) a capture substrate to specifically adsorb
antigens from solution; (2) Extrinsic Raman Labels (ERLs): surface functionalized gold nanoparticles
(AuNPs) to bind to captured antigens selectively and generate intense SERS signals, which contain both
capture antigen and SERS active readout molecule (4-nitrobenzenethiol (4-NBT))
Subnanomolar detection of tuberculosis biomarker MPT64 in sandwich sers immunoassay on novel low -cost substrate
The use of SERS for detection, analysis and imaging has attracted great interest in the
past decade owing to its high sensitivity and molecular fingerprint specificity. There is an increasing
interest in scientific community to SERS as it becomes a versatile method for early medical diagnostics
and reliable detection of major health threats to humans (e.g. cancer, tuberculosis, etc) and animals [1].
The key component of our SERS-based immunoassay include:1) a capture substrate to specifically adsorb
antigens from solution; (2) Extrinsic Raman Labels (ERLs): surface functionalized gold nanoparticles
(AuNPs) to bind to captured antigens selectively and generate intense SERS signals, which contain both
capture antigen and SERS active readout molecule (4-nitrobenzenethiol (4-NBT))
High sensitivity detection of NBT on novel SERS substrate
Surface-enhanced Raman scattering (SERS) is rapidly evolving as a useful analytical
tool in chemical and biological analysis. The most critical aspect of SERS is the research of efficient SERSactive
substrates, such as nanostructured surface or nanoparticles of noble metals with suitable physical
parameters such as their material, size, shape, and spacing [1]. Generally, Ag and Au substrates are
regarded as one of the best candidates for SERS. Nevertheless, fabrication of SERS substrates with both
high sensitivity and high reproducibility remains difficult, and it is costly for routine SERS detection.
We report the novel combined substrate for highly sensitive Surface Enhanced Raman spectroscopy
(SERS) are capable of detecting 4-nitrobenzenethiol (NBT), as a model Raman active molecule, at very
low concentration
High sensitivity detection of NBT on novel SERS substrate
Surface-enhanced Raman scattering (SERS) is rapidly evolving as a useful analytical
tool in chemical and biological analysis. The most critical aspect of SERS is the research of efficient SERSactive
substrates, such as nanostructured surface or nanoparticles of noble metals with suitable physical
parameters such as their material, size, shape, and spacing [1]. Generally, Ag and Au substrates are
regarded as one of the best candidates for SERS. Nevertheless, fabrication of SERS substrates with both
high sensitivity and high reproducibility remains difficult, and it is costly for routine SERS detection.
We report the novel combined substrate for highly sensitive Surface Enhanced Raman spectroscopy
(SERS) are capable of detecting 4-nitrobenzenethiol (NBT), as a model Raman active molecule, at very
low concentration
Relativistic many-body calculation of low-energy dielectronic resonances in Be-like carbon
We apply relativistic configuration-interaction method coupled with many-body
perturbation theory (CI+MBPT) to describe low-energy dielectronic
recombination. We combine the CI+MBPT approach with the complex rotation method
(CRM) and compute the dielectronic recombination spectrum for Li-like carbon
recombining into Be-like carbon. We demonstrate the utility and evaluate the
accuracy of this newly-developed CI+MBPT+CRM approach by comparing our results
with the results of the previous high-precision study of the CIII system
[Mannervik et al., Phys. Rev. Lett. 81, 313 (1998)].Comment: 6 pages, 1 figure; v2,v3: fixed reference
EUV spectra of highly-charged ions W-W relevant to ITER diagnostics
We report the first measurements and detailed analysis of extreme ultraviolet
(EUV) spectra (4 nm to 20 nm) of highly-charged tungsten ions W to
W obtained with an electron beam ion trap (EBIT). Collisional-radiative
modelling is used to identify strong electric-dipole and magnetic-dipole
transitions in all ionization stages. These lines can be used for impurity
transport studies and temperature diagnostics in fusion reactors, such as ITER.
Identifications of prominent lines from several W ions were confirmed by
measurement of isoelectronic EUV spectra of Hf, Ta, and Au. We also discuss the
importance of charge exchange recombination for correct description of
ionization balance in the EBIT plasma.Comment: 11 pages, 4 figure
Efficient Algorithm for Asymptotics-Based Configuration-Interaction Methods and Electronic Structure of Transition Metal Atoms
Asymptotics-based configuration-interaction (CI) methods [G. Friesecke and B.
D. Goddard, Multiscale Model. Simul. 7, 1876 (2009)] are a class of CI methods
for atoms which reproduce, at fixed finite subspace dimension, the exact
Schr\"odinger eigenstates in the limit of fixed electron number and large
nuclear charge. Here we develop, implement, and apply to 3d transition metal
atoms an efficient and accurate algorithm for asymptotics-based CI.
Efficiency gains come from exact (symbolic) decomposition of the CI space
into irreducible symmetry subspaces at essentially linear computational cost in
the number of radial subshells with fixed angular momentum, use of reduced
density matrices in order to avoid having to store wavefunctions, and use of
Slater-type orbitals (STO's). The required Coulomb integrals for STO's are
evaluated in closed form, with the help of Hankel matrices, Fourier analysis,
and residue calculus.
Applications to 3d transition metal atoms are in good agreement with
experimental data. In particular we reproduce the anomalous magnetic moment and
orbital filling of Chromium in the otherwise regular series Ca, Sc, Ti, V, Cr.Comment: 14 pages, 1 figur
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