No abstract

Introduction. The purpose of the SPR sensor is to quickly and accurately determine the refractive index of the environment with the ability to diagnose the presence of a specific substance. SPR devices and biosensor diagnostic methods for laboratory diagnostics in medicine, veterinary medicine, determination of environmental pollution, for food quality control are being developed. The work is devoted to the development of devices based on the surface plasmon resonance of the “Plasmontest” series, which can be used for refractometric and biosensor applications. The purpose of the paper is to present the development of “Plasmontest” series devices that can be used for laboratory applications, as portable field-research devices and to carry out a comparison of optical circuits of SPR devices, their capabilities and operational characteristics during biochemical and physical experiment. Results. Specific features of the design of devices "Plasmontest" with discrete and aperture optical circuits are outlined. The method of approximation of the resonant SPR curve is proposed to accurately find the value of the resonance minimum. Procedures for normalizing and calibration of devices with aperture optical circuit in single-channel and dual-channel design are developed to improve measurement accuracy. Some features of the developed software for “Plasmontest” series devices are presented. Applications of "Plasmontest" devices for the refractometry and the development of thin-film technological processes as well as for creating the methods of immunosensory detection of a number of bacteria and toxins are described. Conclusions. The work on the creation of “Plasmontest” series devices showed the possibility for creating portable SPR devices and for refractometric, thin film and biosensor studies. It is shown that devices with aperture optical circuitry are the most promising in terms of compactness, reliability and low cost.

No abstract

Introduction. The article describes the optimization of the superconducting antenna design and balancing method of the superconducting antenna of magnetometer. This magnetometer is designed to study the magnetic properties of materials, as well as non-invasive study of the distribution of magnetic particles in organs of small laboratory animals, when toxic particles or drugs are introduced into the animal's body. The superconducting antenna of the magnetometer is a second-order axial gradiometer and is a part of the flux transformer of the SQUID sensor. For stable operation within the dynamic range of the magnetometer, the antenna must have a balance degree of at least 1/1000. Traditionally, it is balanced in a separate tuning module (Helmholtz coils), which creates a homogeneous magnetic field with a high degree of uniformity. The purpose. The problem is that the subsequent displacement of the SQUID magnetometer unit into the measuring complex, even within the laboratory, reduces the degree of balance of the magnetometer due to objects that create a strong gradient magnetic field, which negatively affects the measurements. Results. As a solution of this problem, the some approaches are described in the article. In order to increase the uniformity of the field inside the solenoid and eliminate field distortions at its edges, the using of solenoid with a special arrangement of turns to balance the antenna directly at the measurement site was proposed. The balancing elements for the horizontal components of the magnetic field were eliminated. Also the antenna balancing element in the form of a ring along the vertical component of the magnetic field, which does not violate the symmetry of the antenna was applied. Conclusions. Using this approach, it is possible to optimize the design of the antenna unit and the balancing process of the magnetometer antenna with a sufficient degree of balance in the vertical component directly in the geometric center of the measuring system, which reduced the time of preparing the system for work and improved the metrological indicators of the system. Keywords: superconductivity, SQUID-magnetometry, axial gradiometer, antenna balance, optimization.

No abstract