VCO-based ESR-on-a-chip as a tool for low-cost, high-sensitivity point-of-care diagnostics

Schlecker, Benedikt; Chu, A.; Handwerker, Jonas; Kiinstner, S.; Ortmanns, Maurits; Lips, K.; Anders, Jens

doi:10.1109/icsens.2017.8233896

Cited by 6 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both spectra in Fig. 2b were simulated using the "pepper" function of the EasySpin software package (Stoll and Schweiger, 2006) assuming a spin-1/2 system with Lorentzian broadening. The asymmetry of the line shape in the CW spectrum is included in the simulation via a tailored fitting function according to Eq.…”

Section: Comparison Between Cw-and Rs-eproc Spectramentioning

confidence: 99%

“…All simulations of transient RS-EPR signals were performed by numerically solving the Bloch equations (Tseitlin et al, 2013;Stoll and Schweiger, 2006) in the steady state using EasySpin's "blochsteady" function. A spin-1/2 system with a g value of 2.003, a Lorentzian line shape, and relaxation times T 1 = 110 ns and T 2 = 100 ns were assumed based on previous reports for BDPA (Goldsborough et al, 1960;Mitchell et al, 2011b).…”

Section: Appendix A: Fourier Deconvolutionmentioning

confidence: 99%

See 1 more Smart Citation

Rapid-scan electron paramagnetic resonance using an EPR-on-a-Chip sensor

Künstner

Chu²,

Dinse

et al. 2021

Magn. Reson.

View full text Add to dashboard Cite

Abstract. Electron paramagnetic resonance (EPR) spectroscopy is the method of choice to investigate and quantify paramagnetic species in many scientific fields, including materials science and the life sciences. Common EPR spectrometers use electromagnets and microwave (MW) resonators, limiting their application to dedicated lab environments. Here, novel aspects of voltage-controlled oscillator (VCO)-based EPR-on-a-Chip (EPRoC) detectors are discussed, which have recently gained interest in the EPR community. More specifically, it is demonstrated that with a VCO-based EPRoC detector, the amplitude-sensitive mode of detection can be used to perform very fast rapid-scan EPR experiments with a comparatively simple experimental setup to improve sensitivity compared to the continuous-wave regime. In place of a MW resonator, VCO-based EPRoC detectors use an array of injection-locked VCOs, each incorporating a miniaturized planar coil as a combined microwave source and detector. A striking advantage of the VCO-based approach is the possibility of replacing the conventionally used magnetic field sweeps with frequency sweeps with very high agility and near-constant sensitivity. Here, proof-of-concept rapid-scan EPR (RS-EPRoC) experiments are performed by sweeping the frequency of the EPRoC VCO array with up to 400 THz s−1, corresponding to a field sweep rate of 14 kT s−1. The resulting time-domain RS-EPRoC signals of a micrometer-scale BDPA sample can be transformed into the corresponding absorption EPR signals with high precision. Considering currently available technology, the frequency sweep range may be extended to 320 MHz, indicating that RS-EPRoC shows great promise for future sensitivity enhancements in the rapid-scan regime.

show abstract

Section: Comparison Between Cw-and Rs-eproc Spectramentioning

confidence: 99%

Section: Appendix A: Fourier Deconvolutionmentioning

confidence: 99%

Rapid-scan electron paramagnetic resonance using an EPR-on-a-Chip sensor

Künstner

Chu²,

Dinse

et al. 2021

Magn. Reson.

View full text Add to dashboard Cite

show abstract

“…An implementation of such a smart sensor within an application specific integrated circuit (ASIC) is very advantageous, since it enables in-situ measurements with a high signal-tonoise ratio. An example for a high-end smart sensor application is to measure free radicals in blood samples using a mobile electron spin resonance (ESR) spectrometer [2]. A similar design can be applied for nuclear magnetic resonance (NMR) microscopy [3].…”

Section: Introductionmentioning

confidence: 99%

Precise and Robust Magnetic Field Computations for High-End Smart Sensor Applications

Buchau

2019

Boundary Elements and Other Mesh Reduction Methods XLII

View full text Add to dashboard Cite

Highly precise magnetic field computations are essential for the design of magnets and coils of highend smart sensors in the context of nuclear magnetic resonance (NMR) and electron spin resonance (ESR) applications. Here, requirements for numerical magnetic field computations are that the methods are precise and mainly robust in the sense of reliable results. Non-linear magnetic materials, induced eddy currents, and the infinite surrounding air domain must be accurately considered in the numerical model. To this end, a smart combination of the finite element method (FEM) with the boundary element method (BEM) including a powerful post-processing is proposed with a focus on the region of interest (ROI), which contains the studied sample. Separate BEM domains are defined for the infinite surrounding air domain and the ROI. Then, the computational costs are reduced due to the relatively small number of relevant boundary elements of the surface of the ROI and a precise and efficient evaluation of magnetic fields based on a meshfree BEM post-processing in the ROI is possible. As an example, the numerical formulation, the application of the proposed approach, and numerical results are shown for the homogeneous field of a permanent magnet.

show abstract

Current Trends in VCO-Based EPR

Kern,

Chu,

Anders

2024

Appl Magn Reson

View full text Add to dashboard Cite

In this article we provide an overview of chip-integrated voltage-controlled oscillator (VCO)-based EPR detection as a new paradigm in EPR sensing. After a brief motivation for this alternative detection method, we provide a self-contained overview of the detection principle, both for continuous-wave and pulsed detection. Based on this introduction, we will highlight the advantages and disadvantages of VCO-based detection compared to conventional resonator-based detection. This is followed by an overview of the current state of the art in VCO-based EPR and interesting emerging applications of the technology. The paper concludes with a brief summary and outlook on future research directions.

show abstract

VCO-based ESR-on-a-chip as a tool for low-cost, high-sensitivity point-of-care diagnostics

Cited by 6 publications

References 4 publications

Rapid-scan electron paramagnetic resonance using an EPR-on-a-Chip sensor

Rapid-scan electron paramagnetic resonance using an EPR-on-a-Chip sensor

Precise and Robust Magnetic Field Computations for High-End Smart Sensor Applications

Current Trends in VCO-Based EPR

Contact Info

Product

Resources

About