Electron Spin Resonance Measurement with Microinductor on Chip

Abstract EN

The detection of radicals on a chip is demonstrated.

The proposed method is based on electron spin resonance (ESR) spectroscopy and the measurement of high-frequency impedance of the microinductor fabricated on the chip.

The measurement was by using a frequency sweep of approximately 100 MHz.

The ESR spectra of di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) dropped on the microinductor which is fabricated with CMOS 350-nm technology were observed at room temperature.

The volume of the DPPH ethanol solution was 2 μL, and the number of spins on the micro-inductor was estimated at about 1014.

The sensitivity is not higher than that of the standard ESR spectrometers.

However, the result indicates the feasibility of a near field radical sensor in which the microinductor as a probe head and ESR signal processing circuit are integrated.