Chemical sensors and biosensors

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Course teacher

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Status of the course

Course objectives

Students will get insight into actual achievements in chemical and biochemical sensing systems. Basic principles and kind of chemical and biochemical sensor systems will be presented together with problems that can arise during development process of such sensors systems (sensors material or biomaterial, recognition mechanism, choosing appropriate transducer element, configuration and practical development of sensors. Furthermore, practical applicability of chemical sensors and biosensors in medical, industrial and environmental analysis will be given.

Course enrolment requirements and entry competences required for the course

Learning outcomes expected at the level of the course (4 to 10 learning outcomes)

1. To recognize and characterize sensors systems.
2. To propose and to development novel sensors systems, together with improvement of current ones.
3. To use a knowledge in selection of appropriate sensors systems for various analytes in different area of application.
4. To get specific insight into recognition principles, amplification and transduction of chemical signal into various outcome signals.

Course content broken down in detail by weekly class schedule (syllabus)

1. General aspects and introduction in chemical sensors and biosensors-definition, terminology.
Classification of sensors (electrochemical, optical, piezoelectrical, termal, aqoustic). Phenomenon (recognition mechanism) that can be applied in sensors systems. Novel trends and scopes in sensors development (nanotechnology, nanostructure, ”smart” sensors, in vivio sensors)
2. Basic construction concepts of sensors and biosensors. Example of commercial sensors and biosensors (ion-selective electrodes, glucometer, Elisa assay). Chemical and biochemical recognition mechanism. Recognition elements: ionophores, enzymes, crystals. Criterion for recognition elements selection. Biochemical selectivity and stability of recognition elements-problems.
3. Matrix material of sensors. Role and characteristics of matrixes. Recognition element immobilization methods. Incorporation of recognition elements into various matrixes (gels, polymers: conducting or non-conducting, carbon materials: paste, screen-printing, carbon nanotubes). Covalent binding of enzymes, cross-linking, physical adsorption.
4. Transducer for electrochemical, optical, piezoelectrical sensors. Selection of transducing element. Electrochemical sensors: potentiometric, amperometric. Modiffied electrodes. Preparation of ion-selective electrodes-techniques. Conducting surface, modified layer, signal transducing. Microelectrodes, FET sensors.
5. Optical sensors. Absorption, UV absorption, reflectometry, luminescence. Optical fibers sensors. Intrinsic and extrinsic sensors. Application of optical sensors in sensing of pH, pressure, temperature, humidity. Determination of biomolecules with optical sensors-luciferase in ATP detection and bacterial redox systems with luciferase in NADPH detection.
6. Piezoelectrical sensors. General aspects. Acoustic sensors. Incorporation of recognition elements.
7. Biosensors. Electrochemical, optical, immunosensors, optical sensors. First, second and third generation of biosensors.
8. Examples of the three generation of biosensonsors-amperometric determination of glucose. Redox interference. Oxygen dependence of the signal. Peroxide role. in vitro and in vivo continuously monitoring of glucose. Modern scopes in development of glucometers. Commercialization of sensors.
9. Immunosensors. Antibody-antigen bonding as mechanism of recognition. Electrochemical, optical, immunosensors, optical immunosensors. Examples of immunosensors for hemoglobin, erythrocytes, t-lymphocytes, viruses and bacterial. ELISA test.
10. DNA detection. DNA electrochemical sensors. Electrochemistry of DNA and detection principles. Immobilization of DNA sequences onto different materials. Electrodes processes-hybridization. Enzyme labeled DNA sequences.
11. Bionseors for pesticide detection. Enzymes used for pesticide detection. Basic concepts. Inhibition mechanism. Catalytically based biosensors. Immunosensors for pesticides determination. Enzymes reactivation. Microorganism, issue, cells as recognition elements.
12. Nanomaterial in optical and electrochemical biosensors. Carbon nanotubes (CNT) in biosensors preparation. CNT composite materials.
13. Introduction in direct transfer of electrons by proteins. Protein immobilization techniques. Examples: cytochrome c, myoglobine, hemoglobine. Role of CNT. Direct electron transfer from enzyme onto electrode. Examples: glucose oxidase, catalase, HRP.
14. Evaluation of sensors: selectivity, sensitivity, reproducibility, repeatability. Other types of sensors: impedance sensors, sensors for gases.
15. Highly sophisticated sensors systems: microelectro-machanical systems (MEMS and Bio(MEMS)), Lab-on-a-chip, nanosensors, biochips.
Lab courses:
1. Preparation of potentiometric sensors by incorporation of ionophores in polymer matrix. Components ratio influences onto sensor characteristics. Determination of heavy metals in water. Selectivity of prepared sensor.
2. Amperometric determination of amino acids onto crystal and bismuth modified electrodes. Electrode preparation, characterization, influences of parameters on signal quality.
3. Preparation of the biosensors for determination of glucose. Incorporation of glucoso oxidase into carbon paste. MnO2 as transducing element. Interferences. Role of Nafion® in improvment of the signal. Determination of glucose in real samples

Format of instruction:

Student responsibilities

The 80% presence at lectures and completed all laboratory exercises.