Apparatus, methods, and systems for detecting biomarkers are disclosed. A sensing apparatus for detecting the presence of at least one biomarker in subcutaneous tissue is disclosed, the sensing apparatus including a probe comprising a shaft, and a biomarker detection material coated on at least a portion of the shaft of the probe. The sensing apparatus further includes a sensor communicatively coupled to the biomarker detection material, the sensor configured to detect a change in at least one of an electrical property and an optical property of the biomarker detection material. When a change in the at least one of an electrical property and optical property of the biomarker detection material is detected, the change is indicative of the presence of at least one biomarker.
