credit seminar on application of biosenser.pptx

Food borne disease caused by pathogens have long term effects on social and economic conditions by resulting in a loss of productivity

1. Division Of Veterinary Microbiology Indian Veterinary Research Institute, Izatnagar, Bareilly Topic: Application of biosensors for detection of food borne pathogens in livestock products Presented by : Dr. Tejpal Mvsc 1 St year M-6515 Major credit seminar

2. Introduction Food borne diseases caused by pathogens have long term effects on social and economic conditions by resulting in a loss of productivity. A biosensor is an independent integrated device that provide quantitative or semi-quantitative analytical information by means of biological recognition system in direct spatial contact with the transducer. The first biosensor was developed by Clark in 1956 and further subsequently illustrated by Clark and Lyons in 1962 by sandwiching soluble glucose oxidase, it determines the concentration of glucose.

3. Working principle of biosensors Biosensor are analytical devices that convert a biological response into electrical signal. They consist of a biological recognition element and a transducer, which converts the biological response into electrical signals. Biological recognition element selectively interact with target analyte and produce a measurable response. Transducer detects and converts this signal into measurable output such as voltage or current.

4. Classification of biosensors On the basis of bio receptor: Antibody biosensor Micro-organism biosensor Phage biosensor Enzyme biosensor Bioreceptor is a biomolecule that exploits a biochemical mechanism for recognition, which are responsible for binding the target analyte to the sensor for measurement. (Velusamy et al., 2010) On the basis of transducer: Electrochemical biosensor Optical biosensor Mass sensitive biosensor Nano sensor

5. Electrochemical biosensor Electrochemical biosensors are analytical device that combines the principle of electrochemistry with biological recognition elements to detect the target analyte. Based on their operating principle electrochemical biosensors are of following types: Amperometric biosensor Potentiometric biosensor Impedimetric biosensor Conductometric biosensor

6. An immunosensor based on specific antibody antigen interaction was also constructed for E.coli detection. A DNA sequence specific electrochemical biosensor has been developed for the amperometric detection of E.coli . A new type of electrochemical DNA biosensor based on magnetic beads that detect the vid A gene which encodes the enzyme beta-D-glucornidase produced by E.coli has been developed. E.coli O157:H7 can also be detected using biosensors that employ a ferrocene antimicrobial peptide conjugate on a gold surface based on impedance. An aptamer based electrochemical biosensor for rapid salmonella detection has been developed.

7. A biosensor constructed based on immobilization of the cell wall binding domains of bacteriophage encoded peptidoglycan hydrolases on a gold screen printed electrode was applied to listeria detection. This technology uses electrochemical impedance spectroscopy for rapid detection of listeria cells. Monoclonal antibodies immobilized on a gold electrode have been used in combination with electrochemical impedance spectroscopy to detect l.monocytogenes .

8. Optical based biosensors Optical based biosensor allow detection of target analyte based on different properties of light like absorption, reflection, refraction, dispersion, infrared, Raman, chemiluminescence, fluorescence and phosphorescence. Optical biosensors are most commonly used for the detection of bacterial pathogens due to their sensitivity and selectivity. A label free optical fibre sensor technique that works on the basis of change in light absorbance at 280 nm in the presence of target analyte has been used successfully for E.coli detection. Optical SPR biosensors are highly sensitive for campylobacter detection when specific antibodies against the target campylobacter population are used.

9. Raman spectroscopy It is an optical technique based on inelastic light scattering phenomenon to detect an analyte via molecular bond vibrations. The Raman spectroscopic techniques commonly used for food safety include micro-Raman spectroscopy, Raman imaging and surface enhanced Raman spectroscopy.

10. Fourier transform infrared (FT-IR) spectroscopy It is a non destructive computational technique which involves the collection of spectra based on calculations and evaluation off the coherence of a radiative source with aid of space domain or three domain measurement of EM radiation or any other type of radiation. It has been reported that FT-IR technique can be used directly on the surface of food to produce biochemically interpretable “fingerprints”. FT-IR spectroscopy can be implemented to detect E.coli O157:H7 from ground beef. (Davis et al.,2010)

11. Surface plasmon resonance (SPR) SPR is able to detect minor changes in the refractive index , which occur when cell binds to receptor immobilized on the transducer surface and it measures change of angle of reflected light as a function of change of density of medium against time . The detection of bacteria by SPR requires specific antibodies against the target bacteria, which are immobilized on surface of the gold film and specially bind to target bacteria to generate SPR signals. New DNA based SPR biosensor have been proposed to detect salmonella based on InvA gene . A modified SPR apparatus has been developed for E.coli detection in less than 20 minutes.

12. Mass sensitive biosensors The principle mode of mass analysis relies on the account of piezoelectric crystals which can be made to vibrate at a specific frequency with the application of an electrical signal of a specific frequency. There are mainly two types of mass based sensors used as: 1.Surface acoustic wave (SAW) 2.Bulk wave (BW) or quartz crystal microbalance (QCM) When antibody coated piezoelectric sensor’s surface is placed in a solution containing pathogens, the attachment of the agent to the antibody coated surface results in an increase in the crystal mass and thus provides increase to corresponding frequency shift . (Paramanik et al.,2013)

13. Nano sensors Nano sensors are generally used for the measurement of biological response as well as for conversion of biological response into output signals for analysis. Commonly used nanomaterial in various biosensors are carbon nanotubes, silicon nanoparticles, magnetic beads, graphene oxide and gold nanoparticles. An AUNPs conjugated with E.coli O157:H7 antibodies is used for detection of this strain in milk.

14. These can be placed directly into the packaging material where they would serve as “electronic tongue ” or “noses” by detecting chemical released during food spoilage. Wireless magnetoelastic biosensors are used for the rapid sensitive and direct detection of salmonella on eggshells . A DNA aptamer magnetic bead and quantum dot sandwitch assay was developed using aptamer sensors against mgcl2 extracted surface proteins from campylobacter species. Hybridization reactions with a covalently immobilized DNA probe is used to develop a paper based microfluidic device for detection of L.monocytogenes that yields high sensitivity and reliability.

15. Advantages of biosensors: High sensitivity Specificity Rapid detection Portability Reduced sample size Disadvantages of biosensors: High cost Complexity Stability Interference Limited range of detection

16. Conclusion Biosensors show greater potential for detection of pathogens in food. Rapid, sensitive, specific method have to be developed for detection of food borne pathogenic bacteria to ensure food safety. A variety of enzyme, antibody, nano sensor and microbial based biosensors using optical, electrochemical and acoustic signal transducers have been reported to measure a significant number of food borne pathogens from the livestock products.

17. References Choudhary, U. (2019). Biosensors for detection of food borne pathogens. Yasmin, J., Ahmed, M. R., & Cho, B. K. (2016). Biosensors and their applications in food safety: a review.  Journal of Biosystems Engineering ,  41 (3), 240-254. Ali, A. A., Altemimi, A. B., Alhelfi, N., & Ibrahim, S. A. (2020). Application of biosensors for detection of pathogenic food bacteria: a review.  Biosensors ,  10 (6), 58. Thakur, M. S., & Ragavan, K. V. (2013). Biosensors in food processing.  Journal of food science and technology ,  50 , 625-641. Awang, M. S., Bustami, Y., Hamzah, H. H., Zambry, N. S., Najib, M. A., Khalid, M. F., ... & Abd Manaf, A. (2021). Advancement in salmonella detection methods: From conventional to electrochemical-based sensing detection.  Biosensors ,  11 (9), 346. Park, J. Y., Park, K., Ok, G., Chang, H. J., Park, T. J., Choi, S. W., & Lim, M. C. (2020). Detection of Escherichia coli O157: H7 using automated immunomagnetic separation and enzyme-based colorimetric assay.  Sensors ,  20 (5), 1395.

18. Y. Chai, S. Horikawa, A. Simonian, D. Dyer and B. A. Chin, "Wireless magnetoelastic biosensors for the detection of Salmonella on fresh produce,"  2013 Seventh International Conference on Sensing Technology (ICST) , Wellington, New Zealand, 2013, pp. 174-177, doi : 10.1109/ICSensT.2013.6727637 .

19. Any questions??