Disclosed herein are biosensor systems and related methods for detecting analytes in aqueous and biologic environments. A biosensor system for detecting binding of an analyte of interest may include a detector configured to detect a change in an electrical property on a surface thereof. The detector may be a FET. The system also may include a passive layer disposed on a top surface of the detector. Further, the system may include a hydrophobic layer disposed on the passive layer. The system also may include a receptor-attachment material configured for binding to an analyte. A receptor may bind to the analyte, and the receptor may be attached to the receptor-attachment material. The binding of the analyte to the receptor can cause the change of the electrical property at the surface. In response to the change for example, a current may change for indicating the binding of the analyte to the receptor.