AdUp Sense 2019

AdUp Sense 2019

AdUp Sense is a team from the Uppsala University competing in SensUs 2019 event. For SensUs 2019, AdUp Sense investigated the possibilities for creating a biosensor which is able to measure the concentration of Valproate. The full TRD can be found [ via this link]

Method

A system consisting of graphene oxide (GO) coated screen-printed electrode (SPE) modified with a capture antibody specific for Humiran is used. Surface modification, as well as antibody binding events, lead to changes in the electrochemical properties of the electrode surface which can be used to determine the analyte concentration.

Molecular Recognition

The graphene oxide covered working electrode is activated using EDC/NHS chemistry. Unreacted active sites are then quenched with the addition of 4 μl of 0.5% BSA. An analyte sample is then added onto the electrode surface and allowed to incubate for 30 minutes. The electrode is then rinsed with PBS solution. Finally, a redox couple such as potassium ferrocyanide/ferricyanide is applied onto the electrode to enable a proper measurement.

Physical Transduction

Differential pulse voltammetry (DPV) is used for the readout and an equimolar mixture of the potassium ferricyanide/ferrocyanide redox couple acts as a probe for the signal generation. The current is measured as a function of time and potential between the indicator and reference electrode. As the potential increases towards the redox potential of the probe, it starts undergoing redox and a current up to a peak value is produced. The current is subsequently brought into a diffusion-controlled state and as a result, the total current response takes its shape as a peak. The immunocomplex restricts the surface availability for the redox probe, which lowers the number of redox events and therefore reduces the current signal. Measurements are performed after the immobilization procedure to achieve a baseline which is compared to the signal obtained after analyte incubation on the electrode. Samples with known concentrations of the analyte are used to prepare a calibration curve which can then be used to quantify the amount of the analyte in an unknown sample.

Cartridge

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Reader Instrument

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Prizes

None