Overview
of biosensor manufacturing process:
A biosensor incorporates a biological sensing element, such as an
enzyme, antibody, antigen, nucleic acid etc. which is associated with a
physiochemical transducer. When an analyte is presented to the
transducer, a chemical reaction takes place that provides an electrical
signal that is proportional to the concentration of the analyte.
The process requires:
- The
base electrode - Typically the base is made
from plastic. A number of elements can be printed onto the plastic,
including:
- The
biological sensing element is then applied to the transducer.
The printing process (e.g. screen printing) is unsuitable for most
biological materials,
particularly when high temperatures used to cure the printed
electrodes. An alternative is to dispense the material dissolved or
suspended in buffer. BioDot's range
of Aspirate and Dispense (AD series) systems uses its proprietary
BioJet™ non-contact technology to deliver "on the fly"
dispensing. The drop-on-demand technology allows quantitative
dispensing from 20 nL to 4 µL in a given drop.
Often, the researcher will need to experiment with a wide range of
variables when developing a biosensor. These include:
- Changing drop volume while maintaning
low CVs
- Adjusting drop chemistries
- Adjusting drop spacing or pitch
- Applying multiple analytes
- Addition of polymers forming networks
that favor accessibility of analyte or exclude filtration contaminants.
The BioJet Plus system combines high precision dispensing (typically
less than 3% at 1 µL, 5% at 100 nL), with accurate XYZ stage
movement (+/- 10 µm in X and Y). Its ability to aspirate and
dispense, coupled with high level of control of the drop-on-demand
volumes, allow combinatorial approaches to sensor development.
From a manufacturing viewpoint, BioDot offers a wide range of platforms
with the BioJet Plus technology to allow researchers to scale-up their
ideas from bench, through pilot production onto full manufacturing with
a minimum of process development issues. On-the-fly dispensing allows
extremely high manufacturing output with a typical card of 250 sensors
being dispensed in less than 30 seconds.
- The process continues to where the
individual sensors need to be cut from the cards.
BioDot offers both rotary and guillotine cutters with a variety of
blade options to suit the researcher's specific material. Furthermore,
the cutting systems can incorporate magazine card feed and bottle
collection to automate the manufacturing process.
In its simplest definition, a biosensor is a device for the detection
of an analyte that combines a biological component with a
physicochemical detector component. Biosensors typically use with
printed circuits, surface acoustic wave (SAW) or other acoustic
elements and incorporate electronics or signal processors (readers)
that are primarily responsible for the display of the results in a
user-friendly way. Despite its long history in diagnostics, the glucose
biosensor is still the most prevalent biosensor in the marketplace
today. Moreover, the demand for glucose monitoring can be expected to
increase. At the time of writing, the estimated diabetic population in
the United States is approximately 20 million persons, with only 66% of
those diagnosed and receiving treatment. In addition to conventional
medical sensors, pharmaceutical research is promoting development of
new rapid assay biosensors to speed drug discovery. Military and
security applications are driving new rapid detection biosensors
against bio-warfare agents. Biosensor formats have been used in food
safety, environmental monitoring, and in both hospital and public
sanitation. Environmental monitoring includes long standing
applications for waste water, and also detectors for industrial gases
and particulates.
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