We are 13 students from multiple disciplines RWTH Aachen University who compete in this year's SensUs competition. We build a biosensor to measure vancomycin, which is a last-resort antibiotic. Drug level monitoring is highly important to enable correct dosing. Incorrect dosing of Vancomycin can result in serious side effects as well as drug resistance. A small sized biosensor integrated into a portable device holds great potential to immediately measure Vancomycin concentration, enabling nurses and physicians to maximize treatment effectiveness for individual patients.
We designed a biosensor to measure the concentration of the last-resort antibiotic Vancomycin in blood plasma via electrical impedance spectroscopy. The plasma passes gold electrodes that are covered with a conductive polymer (Polypyrrole) and antibodies that bond with Vancomycin. The bonding causes a chemical reaction that can be translated to an electric signal. The conductive polymer provides an optimal environment for bonding and amplifies the electrical signal, helping to achieve better measurement results. The signal is processed computationally and translated to a value for concentration of vancomycin.
What is novel about our sensor is the use of a Polypyrrole matrix (see illustration: light blue area) to immobilize Vancomycin antibodies on gold electrodes to amplify the signal. This approach improves the measurement results and avoids unwanted bonding of molecules. We hope to have achieved a fast and accurate way to measure Vancomycin concentration to help ensure safe and effective dosing.
We started as a small group with only five members and kept growing to a group of 13. Each of us has a different background, with majors ranging from Bioengineering, Electronics and Computer Science to Technical Communication, a variety that has been totally enriching for our project.
designed the structure of the the microsensor in CAD software. The different layers include the gold electrodes and microfluidics channels. The design served as the basis for the fabricated sensor.
fabricated the designed chip in the cleanroom fabrication laboratory. Ensured that all the produced chips are according to the desired requirements and meet the set criteria. Produced the gold electrode surfaces and the fluid channels based on previously established procedures and tools.
designed a robust structure that holds the sensitive microchip in place while being in use. The printed circuit board (PCB) provides the necessary ports that connect the sensor to the signal analyzer.
performed the antibody immoblization within a polypyrrole matrix on gold the electrodes to allow for vancomycin binding to the surface. Chronoamperometry was used to polymerize pyrrole providing a superior control during the process.
developed a small tool to analyse the data produced during measurement. This data can be read from already stored data files or from a live experiment. After getting the data, the tool creates graphs and calculates the searched concentration.