ESR is an indispensable tool in the fields of chemistry and materials research for any situation where paramagnetic materials are involved. In order to get a better understanding of the substance structure and behavior, spinflex analytical solutions can meet your needs in a simple and very “user friendly” way. Measurements can be carried out at room temperature or at cryogenic conditions and on very small volume samples. For example, the chemistry topics where spinflex products can be helpful are:

publications employing spinflex products

Electron spin resonance microfluidics with sub-nanoliter liquid samples

(Journal of Magnetic Resonance Open 2–3, (2020), 100005

Microfluidics is a well-established technique to synthesize, process, and analyze small amounts of materials for chemical, biological, medical, and environmental applications. Typically, it involves the use of reagents with a volume smaller than ~ 1 micro-l—ideally even nano- or picoliters. When the sample of interest contains paramagnetic species, it can in principle be quantified and analyzed by electron spin resonance (ESR) spectroscopy. However, conventional ESR is typically carried out with a sample volume of ~ 1 ml, thereby making it incompatible with most microfluidics applications. This is a key capability to measuring unique properties such as nanoscale real-space diffusion and quantum spin diffusion. All of the experiments are performed at room temperature, making our technique compatible with future microfluidics applications that might employ a complete system of compact resonators, microfluidic chips, miniature magnets, and a compact ESR-on-a-chip spectrometer. This could result in a completely new approach to processing and measuring paramagnetic liquid samples for use in a variety of chemical, biological, medical, and environmental applications.

Electron-Spin-Resonance Dipstick

(Analytical Chemistry, 90, (2018), 7830)

Electron spin resonance (ESR) is a powerful analytical technique used for the detection, quantification, and characterization of paramagnetic species ranging from stable organic free radicals and defects in crystals to gaseous oxygen. Traditionally, ESR requires the use of complex instrumentation, including a large magnet and a microwave resonator in which the sample is placed. Here, we present an alternative to the existing approach by inverting the typical measurement topology, namely placing the ESR magnet and resonator inside the sample rather than the other way around. This new development relies on a novel self-contained ESR sensor with a diameter of just 2 mm and length of 3.6 mm, which includes both a small permanent magnet assembly and a tiny (∼1 mm in size) resonator for spin excitation and detection at a frequency of ∼2.6 GHz. The spin sensitivity of the sensor has been measured to be ∼1011 spins/√Hz, and its concentration sensitivity is ∼0.1 mM, using reference samples with a measured volume of just ∼10 nL. Our new approach can be applied for monitoring the partial pressure of oxygen in vitro and in vivo through its paramagnetic interaction with another stable radical, as well as for simple online quantitative inspection of free radicals generated in reaction vessels and electrochemical cells via chemical processes.

Additional Publications

Recent trends in high spin sensitivity magnetic resonance

Authors name:
Yakir Ishay

Journal of Magnetic Resonance 280, (2015), 26-35

Advanced surface resonators for electron spin resonance of single microcrystals

Authors name:
Nir Dayan, Yakir Ishay

Review of Scientific Instruments 89, (2018), 124707

A hand-held EPR scanner for transcutaneous oximetry

Authors name:
Helen Wolfson, Rizwan Ahmad

Proceedings 9417, (2015), 941706