Microfluidic Approach for the Detection of Uric Acid through the Electrical Measurement of Atomically Thin MoS2 Field-Effect Transistor

Abstract

There is a demand for biosensors working in vivo conditions, which requires significant device size and endurance miniaturization in solution environments. We demonstrated the detection of the uric acid (UA) molecule, a marker of diseases like gout, whose continuous monitoring is demanded in a medical diagnosis. We used the field effect transistor composed of an atomically thin channel of transition metal dichalcogenides (TMDs). The sensor detection was carried out in the solution environment, for which we protected the electrodes of the source and drain from the solution. A microfluidic channel controls the solution flow that can realize evaporation-free conditions and provide an accurate concentration and precise measurement. We detected a systematic change of the drain current with the concentration of the UA in isopropyl alcohol (IPA) solvent with a detection limit of 60 nM. The sensor behavior is reversible, and the drain current returns to its original value when the channel is washed with pure solvent. The results demonstrate the feasibility of applying the MoS 2-FET device to the UA detection in solution, suggesting the possible use in the solution environment.