SENSOR AND SCREENING METHODS
LEARNING OUTCOMES OF THE COURSE UNIT
Knowledge of the advanced instrumental analytical techniques; understanding and prediction of the structure-properties relationship of complex systems; critical evaluation of complex problems and proposal of specific solutions;
The student is able to critically evaluate the quality parameters of alternative analytical techniques according to the nature of the experimental problem; ability to evaluate the potential and the limits of the most advanced analytical and characterization techniques; ability to find and evaluate sources of information, databases, literature;
Knowledge and understanding: Definition, working principle and applications of the main chemical sensors and screening techniques. Classification of sensors according to the transduction mechanism and type of receptor. Applications in the environmental, food and pharmaceutical fields. Knowledge of the thermodynamics and kinetics principles relevant to the electrode processes involved in the operation of the amperometric sensors. Biosensors and principals bioreceptors: knowledge of the interaction mechanisms of antibodies and enzymes and their applications for development of enzymatic sensors and immunosensors. Applications in clinical and toxicological fields. Illustration of the working principles and applications of screening techniques based on "ELISA" (Enzyme Linked Immunosorbent Assay) assays. Knowledge of the functional and applicative principles of the "Lateral Flow ELISA" applied in the clinical field on physiological fluids.
COURSE CONTENTS SUMMARY
The contents of the course are an overview of the main chemical sensors and their mechanisms of signal transduction. Are also addressed and depth aspects concerning the materials used as substrates for the development of sensors, the theoretical principles on which their working principle is based, and the methods used for their characterization.
The course is articulated into the following points:
-Definitions, characterization, quality parameters of the sensors.
-Potentiometric Sensors: Basic thermodynamics of electrochemical interphase potentials; ion-selective electrodes based on solid and liquid membranes; ionic receptors and ionophores, calibration procedures and assessment of quality parameters. Practical examples: automatic analyzers of electrolytes and gases dissolved in the blood samples; glass electrode for pH measurement, "Lambda" probe for the combustion control in the engines and for the management of the operation of catalytic converters.
-ISFET and MOSFET Sensors: Retrieve on the properties of semiconductors; “n-p" junctions; diodes and photodiodes; principle of operation of the field effect transistors (FET); combination of FET with ion-selective membranes (ISFET) and with films of metal mixed oxides ( MOSFET).
-Amperometric Sensors: Elements of electrodic thermodynamics and kinetics, mechanisms for mass transport and electronic transfer; reversibility of a response; Butler-Volmer equation and its graphical representation; instrumentation; electrodes modified with composites and nanocomposites active materials; conducting polymers and processes of modification of the electrode surface; miniaturization of electrodes and instrumentation, "screen printed" electrodes; applications in environmental, food and clinical samples
-Biosensors: Properties of bioreceptors as antibodies, enzymes and conjugates haptens; operating principle of competitive and non-competitive immunosensors; immobilization of bioreceptors of nanomaterials for the production of nanobiocomposite substrates; redox mediators, applications in clinical, environmental and food samples.
-Screening Techniques: General Principles; difference between methods of analysis and screening; immunochemical and immunoenzymatic assays, working principle of the "ELISA" kits (Enzyme Linked Immunosorbent Assay) "Lateral flow" ELISA test on disposable strips; applications in clinical field; examples; clinical analyses, determination of antibodies and biomarkers related to disease in blood samples, pregnancy and ovulation tests etc.
Peter Grunder – “Chemical Sensors: an introduction for scientists and engineers” Ed. Springer
The training aid will be supplemented by lecture notes provided by the professor.
ASSESSMENT METHODS AND CRITERIA
The candidates to the examination will choose and present the content of a scientific publication (among international journals) related to the topics treated in the course. The presentation will be followed by an examination aimed to assess the overall skill and knowledge of the students.
Frontal lectures and sessions of calculation and simulation. Visits to the research laboratories of the professor are also planned in order to illustrate the devices concerning the course and how they work.
See the "Contents" section