CHEMICAL SENSORS FOR THE ENVIRONMENTAL MONITORING

The course provides theoretical and practical knowledge on chemical sensors and their application to environmental monitoring. It introduces the main principles of sensor design, operation and validation, with particular attention to the detection of pollutants in air, water and soil. Students will learn how chemical information can be converted into measurable signals and how sensor-based technologies can support sustainable environmental management, risk assessment and decision-making.
The course covers the fundamentals of chemical sensing, the role of the recognition elements, the different transduction mechanisms at the basis of signal collection. The student will learn how to define the different analytical performance (selectivity, sensitivity, detection limits, response time, lifetime, linearity range, limit of detection, reproducibility, repeatability) and how to choose the best sensor configuration on the basis of these properties.
Different classes of sensors will be discussed, including electrochemical, optical, mass-sensitive, semiconductor, nanomaterial-based and biosensors, giving explicative examples of all of the in the environmental applications. Case studies will address the monitoring of inorganic and organic pollutants, heavy metals, nutrients, pesticides, volatile organic compounds, greenhouse gases and emerging contaminants.
Laboratory and practical activities will include sensor preparation and application to environmental analysis.

Knowledge and understanding
- Understand the fundamental principles of chemical sensors, including recognition processes, transduction mechanisms, signal generation and analytical performance parameters.
- Describe and compare different classes of sensors for different applications

Ability to apply knowledge and understanding
- Identify suitable sensing strategies for the detection and monitoring of environmental pollutants in air, water and soil.
- Evaluate sensor performance, considering sensitivity, selectivity, detection limit, response time, lifetime, stability, reproducibility, linearity range and limit of detection.
- Apply chemical sensors to environmental case studies, including the monitoring of heavy metals, nutrients, pesticides, volatile organic compounds, greenhouse gases and emerging contaminants

Making judgements
- Interpret experimental data obtained from sensor-based measurements and assess their reliability in relation to reference analytical methods.
- Recognize the advantages and limitations of sensor-based monitoring systems compared with conventional laboratory techniques.

Communication Skills
- Present and discuss the analyses performed with sensors, with particular reference to the specific analyte.
- Present and discuss orally the results obtained using appropriate technical terminology.

Learning Skills
- Independently consult technical documentation and scientific literature

Basic knowledge of chemical equilibria and reactivity of chemical species
Basic principles of physics

Introduction to the use of sensors for the detection of target species. Definition of analysis off-line, at-line, in-line and on-line. Point-of-use analysis and continuous monitoring.
Analytical performances: accuracy, reproducibility, repeatability sensitivity, selectivity, detection limit, response time, lifetime, linearity range and limit of detection.
Parts of a sensor: recognition elements, transducer, signal elaborator
Classification of chemical sensors.
Sensors for the analysis of atmosphere, air and air pollutants.
Sensors for the analysis of water and water pollutants
The problems related to the analysis of soil

Material provided by the teacher on Moodle

The assessment is done through an oral test on the topics covered during the lectures (theoretical part) and the evaluation of written reports related to the experiences performed in the laboratory.
The oral exam starts with the discussion of an applicative example of a chemical sensor used to the environmental control proposed by the student. During the discussion, the student will discuss the basic principles at the basis of the signal recording and the approaches used for the definition of the analytical performance. The exam will also cover different theoretical aspects considered during the lectures. The student will have to expose the various topics in a formally and scientifically correct language, demonstrating the ability to link different theoretical aspects treated, and their correlation with the experiences carried out in the laboratory. Depending on the ability to discuss the required topics, the exam lasts between 30 to 45 minutes.

oral

The instructor is responsible for ensuring the authenticity and originality of all examinations and coursework. In cases of suspected academic misconduct, an additional on-site assessment may be required during the exams, which may differ from the standard format.

The oral exam scores 66% of the final grade, while the laboratory reports score 33%.
The oral exam will cover two topics from different parts of the program, assessing theoretical knowledge, language skills, and the ability to extract specific concepts from general problems. Each topic, considered as a whole, is assigned a score from 0 to 10.
Each of the three reports is assigned a score from 0 to 3.5, based on the accuracy of the answers to the questions posed by the instructor, the language used, the correct graphical representation, and the processing of experimental data.

Teaching will take place through 15 lectures (30h) and 3 lab experiences (18h).
The lectures will be supported by slides containing schemes and pictures concerning the different arguments. They will be available of the Moodle portal before the class to help the student to follow the discussion and to integrate the schemes with the discussion in the lecture. The slides will also support the study and the preparation to the exam.
The laboratory includes a series of experimental measurements to apply the theoretical knowledge obtained during classes in real examples. Students will work in groups (3-4 people for each group) following a procedural description provided before the lab session. The students will be invited to elaborate the results obtained during the lab experience and to report the main conclusions in a form of brief report that will be sent and evaluated before the exam.

This subject deals with topics related to the macro-area "Natural capital and environmental quality" and contributes to the achievement of one or more goals of U. N. Agenda for Sustainable Development