Biosensors Quiz 1 Flashcards
What do physical sensors measure?
physical things such as force, pressure, temp
What does a chemical sensor do?
transform chemical energy into another form of energy that is useful, it is SELF contained and provides real time information, it performs recognition AND transduction
What is a chemical sensor/ analytical device that does not have a recognition function called?
It is called a concentration transducer
What is a biosensor?
An analytical device that turns a biological signal into an ELECTRICAL signal. It contains a biological recognition element BRE and a transducer. The sensing element and the transducer can be two distinct elements that are packaged together.
What is a molecular sensor/nanosensor?
a sensor that has two distinct units, one binds to analyte and the other changes some property of the analyte. Mol sensors are not chemical sensor because they miss the transducer, these are also called ADVANCED ANALYTICAL REAGENTS
What are the 5 biosensor components?
1) Bioreaction
2) Transducer to electrical signal
3) Amplifier
4) Processor probably by some chip
5) Displayed or used for actuation
What is an analyte or determinant?
A substance thats chemical properties are being measured and identified.
What does a bioreaction do?
Convert substrate to product
What occurs in affinity binding?
There is a reversible covalent bond between two chemical species.
What is ion recognition?
this method occurs when materials and reagents have an electric charge opposite to that of the analyte of interest.
What occurs with recognition by nucleic acids?
Nucleic acid hybridization, where a short nucleic acid (capture probe) is used to detect the analyte nucleic acid.
What occurs in recognition by enzyme?
involves substrate – enzyme complex formation, chemical conversion of bound substrate and product release.
What are the different assay formats?
Direct binding which includes immunoassay and hybridization
Sandwich assay
Displacement assay
replacement binding
What is Immunoassay format?
the antibody in the solution
binds to the immobilized antigen or vice versa.
What is hybridization assay format?
DNA in the solution, binds to complimentary DNA on the surface which is immobilized.