Early detection of dengue is essential to mitigate its impact, as delays in diagnosis can worsen disease severity and increase mortality rate. An alternative to the standard dengue diagnosis is the use of electrochemical biosensors for rapid dengue detection. This study presents the design and development of a portable, flexible electrochemical biosensing device for early dengue virus detection using Integrated Electrochemical Quartz Crystal Microbalance (IEQCM). IEQCM biosensor is a combination of piezoelectric and electrochemical biosensors that provides dual functionalities in a single measurement platform. In this work we demonstrate the functionality of the IEQCM sensor for dengue detection. The IEQCM is connected to our portable potentiostat, fabricated on a flexible printed circuit board. This device enables rapid and early detection by targeting the NS1 antigen through specific antigen-antibody binding, offering electronic readouts and the potential to differentiate between various dengue variants. Cyclic Voltammetry (CV) was measured using a baseline solution (Potassium Ferrocyanide) to verify the functionality of the flexible potentiostat integrated with IEQCM sensor due to its stable electrochemical behaviour. CV measurements show an ΔEp of 0.132 V, comparable to the commercial EmStat Pico potentiostat. To complement the CV results, Electrochemical Impedance Spectroscopy (EIS) was measured using the EmStat Pico potentiostat. EIS measurements were done on bio-recognition element (NS1 antibody) which selectively binds to the analyte (NS1 antigen) in dengue samples. The NS1 dengue antigen was detected with a Limit of Detection (LoD) of 2.31 ng/mL and a Limit of Quantitation (LoQ) of 6.99 ng/mL, showing an absolute error of approximately 5% compared to previous studies. These findings affirm that this designed potentiostat is a viable tool for dengue diagnosis.