JulietteB-cri
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3 years ago Cesewski, E., & Johnson, B. N. (2020). Electrochemical biosensors for pathogen detection. Biosensors and Bioelectronics, 159, 112214. https://doi.org/10.1016/j.bios.2020.112214
An interesting review of electrochemical biosensor-based pathogen detection. They discussed about the different:
Transduction elements
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electrochemical cell where the main component = working electrode three electrode format (working , auxiliary & reference)
for potentiostatic system two electrode format (working & auxiliary) for EIS (electrochemical impedance spectroscopy) -
types of electrodes (metal, ceramic….)
Biorecognition elements
e.g. antibodies, aptamers, imprinted polymers
- Antibodies are the most commonly used - can be labeled with fluorescent tags (label-based approach). Both monoclonal and polyclonal Ab enable the selection of pathogens but they vary in terms of method selectivity binding affinity
- Oligosaccharides
- Oligonucleotides ssDNA aptamers are commonly used pathogen detection using electrochemical biosensors. Aptamers = single stranded oligonucleotides able to bind different molecules with high affinity and selectivity. They are isolated from a large random sequence pool by using systematic evolution of ligands to select them. Their use has not replaced yet traditional biorecognition elements such as antibodies.
- Phages infect and replicate in bacteria through selective binding via tail-spike proteins Classified by selectivity and structure E.coli T4
Applications to pathogen detection
Medical diagnosis application
identification and quantification of pathogens in body fluids NOTE: The same principle can be applied to plants (plant disease related topic?)
Improvements
Detection of plant pathogens!!!!! Low-cost, single-use portable biosensors
Bhalla et al. (2016). Introduction to biosensors. Essays in Biochemistry, 60(1), 1–8. Juliette 21/03/2021
A good review to have the basis about biosensors i.e. what it is, how it works, their applications and some examples. The characteristics of part is really interesting
Recap of the article
1. Components of the biosensors
analyte: the substance of interest that needs detection (e.g. insulin) bioreceptor: molecule that specifically recognizes the analyte. transducer: convert one form of energy into another - its role is to convert the bio-recognition event into a measurable signal. electronics: processes the transduced signal and prepares it for display i.e. complex electronic circuitry display: user interpretation system aka a combination of hardware and software that generates results of the biosensor in a user-friendly manner.
2. Characteristics
Selectivity: ability of a bioreceptor to detect a specific analyte in a sample containing other components. Reproducibility: ability of the biosensor to generate identical responses for a duplicated experimental set-up. Stability: degree of susceptibility to ambient disturbances in and around the biosensing system. Really crucial in the case of long incubation steps and/or continuous monitoring. Sensitivity: so called LOD (limit of detection) is defined by the minimum amount of analyte that can be detected by a biosensor. Linearity: shows the accuracy of the measured response to a straight line, mathematically represented as y = mc withc is the concentration of the analytey the output signalm the sensitivity of the biosensor. It can be associated with the resolution of the biosensor and range of analyte concentrations under test.