Other affiliations: Oak Ridge Associated Universities, Indian Institute of Technology Kharagpur, Shanghai Jiao Tong University ...read more
Bio: Thomas Thundat is an academic researcher from State University of New York System. The author has contributed to research in topics: Cantilever & Scanning tunneling microscope. The author has an hindex of 78, co-authored 622 publications receiving 22684 citations. Previous affiliations of Thomas Thundat include Oak Ridge Associated Universities & Indian Institute of Technology Kharagpur.
Papers published on a yearly basis
TL;DR: It is reported here that microcantilevers of different geometries have been used to detect two forms of prostate-specific antigen over a wide range of concentrations from 0.2 ng/ml to 60 μg/ml in a background of human serum albumin and human plasminogen at 1 mg/ml, making this a clinically relevant diagnostic technique for prostate cancer.
Abstract: Diagnosis and monitoring of complex diseases such as cancer require quantitative detection of multiple proteins. Recent work has shown that when specific biomolecular binding occurs on one surface of a microcantilever beam, intermolecular nanomechanics bend the cantilever, which can be optically detected. Although this label-free technique readily lends itself to formation of microcantilever arrays, what has remained unclear is the technologically critical issue of whether it is sufficiently specific and sensitive to detect disease-related proteins at clinically relevant conditions and concentrations. As an example, we report here that microcantilevers of different geometries have been used to detect two forms of prostate-specific antigen (PSA) over a wide range of concentrations from 0.2 ng/ml to 60 µg/ml in a background of human serum albumin (HSA) and human plasminogen (HP) at 1 mg/ml, making this a clinically relevant diagnostic technique for prostate cancer. Because cantilever motion originates from the free-energy change induced by specific biomolecular binding, this technique may offer a common platform for high-throughput label-free analysis of protein‐protein binding, DNA hybridization, and DNA‐protein interactions, as well as drug discovery. It is becoming increasingly evident that high-throughput identification and quantitation of a large number of biological molecules is important for generating a molecular profile that is critical in diagnosis, monitoring, and prognostic evaluation of complex diseases such as cancer
TL;DR: In this paper, it is shown that the resonance frequency of a cantilever can change due to a combination of mass loading and change of spring constant resulting from adsorption of chemicals on the surface.
Abstract: It is well known that bimetallic microcantilevers can exhibit static deflection as a result of thermal effects, including exothermic adsorption of chemicals on their surfaces. It is shown here that the resonance frequency of a cantilever can change due to a combination of mass loading and change of spring constant resulting from adsorption of chemicals on the surface. Cantilevers also undergo static bending that is induced by differential surface stress. The magnitude of these effects depends upon the chemical properties of the surface and upon the amount of material adsorbed. Hence cantilever deflection as well as resonance frequency change can be used as the basis for development of novel chemical sensors.
TL;DR: In this article, the authors used oscillating silicon nitride microcantilevers coated with a thin gold film to detect adsorbed vapors with picogram mass resolution and found that cantilever resonance frequency changes due to surface mass loading as a result of adsorption of mercury vapor.
Abstract: Oscillating silicon nitride microcantilevers coated with a thin gold film have been used to detect mercury vapor in air. Cantilever resonance frequency changes due to surface mass loading as a result of adsorption of mercury vapor. Furthermore, cantilever bending is also altered due to changes in surface stress induced by mercury adsorption on the gold overlayer. Both of these phenomena can be used to quantitatively detect adsorbed vapors with picogram mass resolution.
TL;DR: The emerging approaches reviewed in this article, with reference to their diagnostic potential, include nanotextured surfaces for proteomics, a two-particle sandwich assay for the biological amplification of low-concentration biomolecular signals, and silicon-based nanostructures for the transduction of molecular binding into electrical and mechanical signals.
TL;DR: The deflection of scanning force microscope cantilevers, metal coated on one side, is significantly influenced by both thermal heating and variations in relative humidity as mentioned in this paper, and the deflection can be estimated from shifts in the cantilever resonance frequency with picogram mass resolution.
Abstract: The deflection of scanning force microscope cantilevers, metal coated on one side, is significantly influenced by both thermal heating and variations in relative humidity. For constant relative humidity, the deflection of the cantilever drifts due to laser heating and eventually reaches a steady‐state value. For a thermally stabilized cantilever, the deflection varies linearly with relative humidity. Exposure to other vapors, such as mercury, changes the inherent deflection of the cantilever. Relative amounts of adsorbates on the cantilever can be estimated from shifts in the cantilever resonance frequency with picogram mass resolution. The cantilever deflection as well as changes in resonance frequency due to vapor adsorption can be used as basis for novel chemical sensors.
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.
28 Jul 2005
15 May 2007
TL;DR: In this paper, the authors discuss the role of surface plasmon polaritons at metal/insulator interfaces and their application in the propagation of surfaceplasmon waveguides.
Abstract: Fundamentals of Plasmonics.- Electromagnetics of Metals.- Surface Plasmon Polaritons at Metal / Insulator Interfaces.- Excitation of Surface Plasmon Polaritons at Planar Interfaces.- Imaging Surface Plasmon Polariton Propagation.- Localized Surface Plasmons.- Electromagnetic Surface Modes at Low Frequencies.- Applications.- Plasmon Waveguides.- Transmission of Radiation Through Apertures and Films.- Enhancement of Emissive Processes and Nonlinearities.- Spectroscopy and Sensing.- Metamaterials and Imaging with Surface Plasmon Polaritons.- Concluding Remarks.
TL;DR: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties are equally important.
Abstract: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties * To whom correspondence should be addressed. Phone, 404-8940292; fax, 404-894-0294; e-mail, mostafa.el-sayed@ chemistry.gatech.edu. † Case Western Reserve UniversitysMillis 2258. ‡ Phone, 216-368-5918; fax, 216-368-3006; e-mail, email@example.com. § Georgia Institute of Technology. 1025 Chem. Rev. 2005, 105, 1025−1102