Micro- and Nanotechnologies
Kamil Zukowski
Ph.D.
Warsaw University of Technology - Centre for Advanced Materials and Technologies
Warsaw, Mazowieckie, Poland
In recent years, point-of-care (POC) testing have significantly changed the way of treating many diseases through the ability to quickly monitor the patient's condition. Manufacturers are constantly working to improve the specificity and sensitivity of their tests to make them suitable for performing analyzes in smaller volume of samples. The production cost and use of such solutions is still a big challenge. However, in order to conduct even the most complex analyzes in POC microdevices, it is necessary to develop effective components such as micro-valves, micro-pumps, micro-mixers, etc. They should not inferior to conventional solutions, with a simultaneous low production cost.
Herein, we present a fully integrated diagnostic system for the determination of various analytes in biological samples. This system consists of two parts: a disposable cassette and a reader device. The basic material for the construction of the cassette were polyester films in two versions: two-sided hydrophilic (3M 9962) and two-sided adhesive (3M 9984). A technology for processing these materials was developed based on laser cutting with the use of very popular CO2 gas lasers and temperature-less lamination. The main element of the cassette is a microreactor with an appropriate antibody immobilized on its surface. Detection of the electrochemical reaction product is performed by cyclic voltammetry measurement using screen printed electrodes. Due to the high susceptibility to the absorption of biological components of the analyzed sample on their surface, it was necessary to use a special valve that directs the products of the enzymatic reaction to the electrodes immediately before the measurement. The active elements of the valve are servos that control its operation. However, due to the reduction of the cassette production cost , the servos were incorporated in the reader device. The fluid flow in the cassette is pressure induced. The sample is inserted directly into the opening in the cassette. Then, it is pushed inside the cassette by the silicone cap, which is also moved by a servo. The reaction carried out in the cassette also requires reagents and washing solutions. They are stored in a blister, which releases its contents into the cassette by the pressure exerted by the arm of the next servo.
Using the developed diagnostic system, the determination of several basic analytes, including CRP was carried out, which confirmed its effectiveness. The developed analytical system is characterized by high versatility, because by selecting the appropriate reagents, it can be simply adjusted to determine various analytes. At the same time, its production technology is characterized by high efficiency at a low unit cost.
Acknowledgments
This work has been financially supported by the National Centre for Research and Development in Poland (grant no. POIR.01.01.01-00-0638/20, POIR.04.01.04-00-0027/17).
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