ORNL's Advanced Biomedical Science and Technology Group has developed various biosensors that
combine laser excitation, fiberoptics probes and biological recognition elements into integrated
devices for ultra-sensitive and selective detection of chemical, biological species in complex
environmental and biomedical samples.
A biosensor is a special type of sensor often used in bioanalysis.
Biosensors can be classified either by their bioreceptor or their
transducer type. A bioreceptor is a biological molecular species
(e.g., an antibody, an enzyme, a protein, or a nucleic acid) or a
living biological system (e.g., cells, tissue, or whole organisms)
that utilizes a biochemical mechanism for recognition.
Bioreceptors are the key to specificity for biosensor technologies.
They are responsible for binding the analyte of interest to the
sensor for the measurement. These bioreceptors can take many
forms, and the different bioreceptors that have been used are as
numerous as the different analytes that have been monitored using
biosensors. However, bioreceptors can generally be classified into
five different major categories: (1) antibody/antigen, (2) enzymes, (3) nucleic acids/DNA, (4) cellular
structures/cells, and (5) biomimetic. Figure 1 shows a schematic diagram of two types of
bioreceptors: the structure of an immunoglobulin G (IgG) antibody molecule, and DNA and the
principle of base pairing in hybridization.
For environmental sensing and medical diagnostic applications, there is a strong need for a truly
integrated biosensor systems that are sensitive and selective and can be easily operated by unskilled
personnel. Some of the currently commercially available technologies have demonstrated their
usefulness, but they are laboratory-oriented and involve relatively expensive equipment and
trained, supervised operation. For practical environmental monitoring, health protection, and