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 W54+^{54+}-W63+^{63+} 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$^{54+}$ to W$^{63+}$ 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