Sensors for Food Testing, Environmental Analysis, and Medical Diagnostics

Dear Colleagues,

With technological advancements, sensors have become indispensable tools in various industries, enabling us to monitor, analyse, and diagnose with unprecedented precision and efficiency. This Special Issue showcases the latest research and developments in sensor technology and its applications in food testing, environmental analyses, and medical diagnostics.

Food Testing with Sensors

In the food industry, sensors play crucial roles in ensuring product safety, quality, and authenticity. Sensors can be used to detect contaminants, allergens, pathogens, and other potential hazards, as well as to monitor freshness, ripeness, and nutritional value. Advances in (bio)sensor technology, nanomaterials, and smart sensors have enabled faster and more reliable food testing, enabling real-time monitoring and early warning systems.

Environmental Analyses with Sensors

Environmental sensors are indispensable in monitoring air, water, and soil quality. They can detect pollutants, toxins, greenhouse gases, and other harmful substances, providing important data for environmental protection and risk assessment.

Medical Diagnostics with Sensors

In the field of medical diagnostics, sensors are used to detect biological active compounds, disease biomarkers, and other biological indicators, as do modern healthcare devices. Biosensors, electrochemical sensors, and optical sensors are some of the most commonly used technologies for rapid, point-of-care testing. These sensors can be integrated into wearable devices, smartphones, and other portable platforms, making diagnostic testing more accessible and convenient for patients.

We invite researchers, engineers, and practitioners from these fields to contribute their work and share their insights.

Dr. Alina Vasilescu
Prof. Dr. Mihaela Badea
Prof. Dr. Jean Louis Marty
Guest Editors

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• sensor technology
• food safety
• environmental monitoring
• medical diagnostics
• biosensors
• nanomaterials
• Smart sensors
• point-of-care testing
• real-time monitoring

Title: Efficient peroxide nanosensors via optical fluorescence and second harmonic generation conversions (SHG)
Authors: Nader Shehata; Sara Noman; Effat Samir; Mohamed Salah; Remya Nair; Ali Hajjiah; Ishac Kandas
Affiliation: 1 Center of Smart Nanotechnology and Photonics (CSNP), Smart CI Research Center, Alexandria University, Alexandria 21544 Egypt; 2 Department of Engineering Mathematics and Physics, Faculty of Engineering, Alexandria University, Alexandria 21544 Egypt; 3 Kuwait College of Science and Technology, Doha Area, 7th Ring Road, Safat 13133, Kuwait; 4 USTAR Bio-innovation center, Utah State University, Logan, Utah 84341 United States. 5 Physics department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt 6 Department of Electrical Engineering, Old Dominion University, Virginia, United States; 7 Faculty of Engineering and Petroleum, Kuwait University, Khaldiya, 13133, Kuwait;
Abstract: The scope of using cerium oxide -gold nanoparticles (CeO2 - Au NPs) as an optical sensor is studied via fluorescence quenching technique. Under violet excitation, ceria NPs have a strong emission in the visible region (~ 530 nm) which clearly proves its strong fluorescence behavior. Here, Au NPs are embedded in-situ with CeO2 NPs. Afterwards, the system is applied in the field of peroxide sensing in aqueous media. The fluorescence intensity is found to be affected by the addition of peroxides into CeO2 - Au NPs. The sensitivity of ceria NPs in peroxide quencher detection is found to be enhanced considerably by the addition of Au NPs. This is because of the plasmonic resonance of Au NPs as it is optically coupled with the fluorescence emission spectrum of ceria. The bandgap of ceria is also found to be decreased by the addition of Au NPs which is due to the creation of more oxygen vacancies inside the non-stoichiometric crystalline structure of ceria. The sensitivity of optical sensing material, ceria–gold NPs with added peroxide is characterized by Stern-Volmer constant and is found to be 0.17627 M−1 which is higher than the case of using ceria NPs only. Ceria–gold NPs with enhanced optical sensitivity can be employed as an optical sensing host for peroxides which plays a major role in many important applications such as biomedicine and water quality monitoring.

Title: Mullite 3D Printed Structures for Humidity Detection
Authors: Y. Milovanov; A. Bertero; B. Coppola,; P. Palmero; J.M. Tulliani
Affiliation: Politecnico di Torino, Department of Applied Science and Technology, INSTM R.U PoliTO-LINCE Laboratory, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
Abstract: Three-dimensional-printed complex mullite structures based on triply periodic minimal surfaces (TPMS), namely, the Schwartz and Gyroid with 2 different thicknesses (Schwartz 1 and Gyroid 1 – 4 mm, Schwartz 2 and Gyroid 2 – 6mm) were fabricated and tested as humidity sensors. The samples were sintered at 1450 °C and tested in the range from 0% to 85% relative humidity (RH) at room temperature to evaluate the effect of geometry and thickness on humidity sensitivity. When exposed to water vapor at room temperature, the impedance value decreased from 75 MΩ under dry air to 31 MΩ under 85 RH% for Schwartz 1 structure (from 133 MΩ to 97 MΩ for Schwartz 2 structure) and from 96 MΩ under dry air to 79 MΩ for Gyroid 1 structure (from 100 MΩ to 14 MΩ for Gyroid 2 structure). The results showed that at 85% RH, the best sensitivity of sensors was achieved for Gyroid 2 structure. Sensors exhibit a good repeatability. There was no interference in the presence of other gases.

Title: Xerogel carbon porous based in lignonocellocic precorsor for nanomolar detection of Taxifolin in peanuts foods
Authors: A. J. Varela Barrios; R. Coneo Rodriguez; R. D. Alaniz; G. Planes; G. D. Pierini*; A. M. Granero*
Affiliation: a Grupo de Electroanalítica (GEANA), Departamento de Química, Instituto para el Desarrollo Agroindustrial y de la Salud (IDAS), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Agencia Postal No 3, 5800, Río Cuarto, Argentina. b Departamento de Química, Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto, Agencia Postal No 3, 5800, Río Cuarto, Argentina.
Abstract: Xerogel carbon porous based in lignonocellocic obtained from municipal waste was used to construct a sensor to determine Taxifolin (Tx). The developed sensor is based on using a xerogel carbon porous dispersion to modify glassy carbon electrodes. Tx exhibits an oxidation peak at 0.61 V (vs. Ag/AgClKCl) in 1 M H2SO4 on the CV electrode modified with the porous material, the participation of protons in the oxidation mechanism was confirmed and an adsorptive control on the modified electrode was observed. As analytical parameters of the developed sensor, a detection limit of 0.5 nM, a linear range between 1 and 100 nM, with a repeatability