1. In how many stages is the transducer manufactured?
Two or three stages:
- screen printing (3-4 different inks)
- polymer coating
- bioreceptor immobilisation
2 and 3 could be coupled.
2. How are the printed transducers stored?
In a box on the shelf, at R/T.
3. How are the polypyrrole-layered transducers stored?
At +4 - +40 °C, sealed to prevent oxygen, moisture and dry out.
4. What special equipment is needed for deposition of the polypyrrole layer?
The regular commercial potentiostat is suitable for this step. Some routine operation and equipment used for galvano-deposition of metals may be used for polymerisation process.
Specifically designed reservoirs with holders and connectors and a simplified device for polymer deposition (replacement for potentiostat, to be developed) may be required for a big scale production.
5. Does deposition of the polypyrrole require a special manufacturing process?
It is a proprietary method, but an electroplating manufacturing method could be simply modified.
6. How are the final transducers coated with biological materials?
Currently passive adsorption or streptavidin- biotin binding is used. However any of the procedures used for solid-phase assays can be applied. Such as, Ink jet printing, dot-printing, pin-printing, screen-printing. Alternatively; incorporation during the electro-polymerisation coating, where the components are added to the polymerisation solution may be applicable although the polymer layer may not be thick enough. The use of a derivitised pyrrole could be a possibility.
Electrochemical coating of bioreceptors after electro-polymerisation. The polymerisation solution is replaced with bioreceptors coating solution. All these alternatives have not been investigated as yet but are alternatives.
7. What volumes of biological materials are needed to coat the final transducers?
Currently 1-2ul of the coating solution is used for passive adsorption. It can be less for other methods already mentioned.
8. Is the electropolymerisation process suitable for low-cost mass-fabrication? If yes, how?
There are a number of sensors with conductive polymers layer available in the market already. That means that an inexpensive way to manufacture them has already been found in principle.
The process of the polymerisation that is performed in UTS is very simple. It does not require sophisticated equipment. Even the regular potentiostat, which we use at the moment, is over specified for our polymerisation regime. The only requirement for large-scale production is that the equipment must be powerful. Other important features are design of reservoirs (the big electropolymerisation cells) for polymerisation and handling sensors after polymerisation process. The whole process has to be designed and built but once that is done then it is relatively simple.
9. How many applied and granted patents does Sensortec have related to UTS?
Link to Sensortec patents page 10. In which development stage is UTS technology? How far is it from commercialisation?
The UTS is at the commercialisation stage. A 12 channel manual biosensor system has been transferred to small scale production. It will be CE marked and available for sale July 2006.
