In the realm of nanotechnology, the detection of biological molecules poses both challenges and opportunities. This paper introduces a novel device structure, the CPB DM-JLTFET, designed to address complications encountered during nanodevice manufacturing, such as temperature coefficient variations and dopant concentration fluctuations. Leveraging charge plasma principles, this innovative structure incorporates an oxide substance in the etching process, resulting in an underlap zone within the nanodevice. Through label-free detection techniques reliant on the electrical characteristics of biomolecules, the CPB DM-JLTFET demonstrates superior performance attributes, including enhanced sensitivity and reduced leakage current compared to existing FET devices. A comprehensive analysis of device factors, including cavity length and thickness, reveals their significant influence on detection sensitivity. Utilizing ATLAS software for simulation, this research underscores the potential of the CPB DM-JLTFET in advancing the development of cost-efficient biomedical diagnostic tools.