Integrated Ammonia Sensor Using a Telecom Photonic Integrated Circuit and a Hollow Core Fiber

Spectral Photoluminescent Parameters of Barley Seeds (Hordéum vulgáre) Infected with Fusarium ssp

We needed effective and sustainable technologies for better microbiological control of crops, including Fusarium. However, photoluminescent UV-Vis methods are potential for diagnosing plant diseases with Fusarium. It has not been sufficiently studied despite the application of these methods for other biological researches. The excitation spectrum of the seeds during infection shifts to the shorter wavelength and a new maximum appears in the region λ ≈ 232 nm. The photoluminescence of infected seeds increases with excitation by radiation of wavelengths λ_e,1  = 232 nm, λ_e,2  = 362 nm and λ_e,3  = 424 nm by 1.33-3.14 times, and λ_e,3  = 424 nm-decreases by 1.1 times. Statistical moments μ₃ and μ₄ , asymmetry and kurtosis change only with short-wave excitation. When analyzing the decomposition of the frequency spectrum into Gaussian curves, the most informative ratio is the ratio of right-handed and left-handed Gaussians under excitation λ_e,2  = 362 nm and λ_e,3  = 424 nm. The ratios of their maxima change during infection by 1.36-3.2 times, and for excitation by radiation λ_e,2 , the frequency boundaries of Gaussians change. The results of measurements and calculations provide a basis for the development of a method and device for photoluminescence diagnostics of fusarium seeds in UV-Vis ranges.

Overtone Spectroscopy for Sensing─Recent Advances and Perspectives

In this perspective, we report an opinion on overtone spectroscopy for sensing and discuss the nature of the opportunities perceived for specialists. New spectroscopic strategies can potentially be extended to detect other common toxic byproducts in a chip-scale label-free manner and to enhance the functionality of chemical and biological monitoring. Nevertheless, the full potential of overtone spectroscopy is not yet exhausted, challenges must be overcome, and new avenues await. Within this Perspective, we look at where the field currently stands, highlight several successful examples of overtone spectroscopy based sensors and detectors, and ask what it will take to advance current state-of-the-art technology. It is our intention to point out some potential blind spots and to inspire further developments.