EIS characterization of a microfluidic paper-based device for the evaluation of prothrombin time

LAZARTE, LUCIANA; BARRAZA DANIELA E.; ALEMAN, MARIANO; MADRID, ROSSANA E.

BUENOS AIRES

Congreso; III Brazil Argentine Microfluidics Congress / VI Congreso Argentino de Microfluídica; 2022

Prothrombin time (PT) is a test that is performed routinely in biochemistrylaboratories (BL), to evaluate the extrinsic pathway and the common pathwayof the coagulation system in a blood sample. Patients under treatment withoral anticoagulants periodically attend the BL, to monitor it. With anincreasing number of anticoagulated patients, there is a growing need todevelop low-cost, portable tests that allow them to assess treatment in thecomfort of their own homes 1 . In recent years, paper has become an alternativefor advanced microfluidic devices, being used as a platform or support forvarious analytical and bioanalytical techniques 2 .It was proposed for this work, to manufacture a paper-based microfluidicdevice that through impedance (EIS), allows to reproduce the PT test.For its fabrication, Whatman N°1 paper was used. Hydrophobic zone wasgenerated with the wax printing technique, using a solid ink printer. At last,carbon electrodes were silk-screened to obtain the device (Figure1).To evaluate its performance by EIS to reproduce the PT test, the followingtests were proposed: a) Evaluation of the optimal work volume and b)Evaluation of the incorporation of ferro/ferri to the PT test. In this test, thevalues ​​of the mean resistance (Rm) and the charge transfer resistance (Rtc),obtained from the "fit circle", were analyzed.The results obtained allowed to establish a) that the optimal workingvolume for this microfluidic device is 10 µl and b) no statistically significantdifferences were determined in the Rtc % values, between measurementsincorporating or not ferro/ferri to the PT assay (Figure2).In conclusion, it was possible to reproduce the PT test in a microfluidicdevice, reducing the volume of reagents to be used by 20 times. And it wasestablished that to perform the impedance measurements of the PT test, theincorporation of ferro/ferri is not necessary.The paper-based microfluidic device developed was easy to manufactureand represents a future alternative to perform the PT test by EIS.