This paper presents the applicability of a high-resolution AlGaN/AlN/GaN metal oxide semiconductor-high electron mobility transistor (MOS-HEMT) for multiple bio detection and analysis of its sensitivity through a charge deduction based approach. The biomarkers of interest chosen in this paper include c-erbB-2, the breast cancer biomarker whose detection from saliva has been modeled. In this approach, the effective gate bias deduced through the model is applied to the fabricated device. High sensitivity of 0.054 mA/μgmL -1 , about nine times higher than the existing/conventional device, is attained here due to the modification of device epi design and use of MOS-gate. Similarly equivalent gate bias/interface charge has been deduced for other biomarkers such as prostate specific antigen, kidney injury molecule, monokine induced by interferon gamma, and glucose oxidase Enzyme, and effective sensitivities of 0.91 mA/μgmL -1 , 0.254 mA/μgmL -1 , 0.48 mA/ngmL -1 , and 2.06 mA/mmolL -1 , respectively, have been attained. The aim of the paper is developing an analytical model to analyze the sensitivity of the fabricated MOS-HEMT device with Al2O3 as gate dielectric (using on wafer testing) before the real packaging or sample introduction to ensure the device usability as a sensor for a dedicated detection. The methodology used here has been validated by comparison of the device sensitivity with real-time pH detection sensitivity. The device showcases high sensitivity of 1.83 mA/pH. The comparison of sensitivity with existing systems proves that the fabricated device overpowers the existing systems with huge marginal increase in sensitivities attained.