High sensitive detection in tumor extracts with SiNW-FET in-air biosensors

Sensitive analysis of proteins is central to disease diagnosis. Their detection and investigation in the tumor tissue can further improve the level of knowledge of the cancer disease by capturing the tumor microenvironment. In previous works we demonstrated that high quality Silicon Nanowire Field Effect Transistors (SiNW-FETs) can be used to sense very low concentration (fM) of pathogenic factors in controlled Phosphate Buffered Saline (PBS). In this work we show, SiNW-FETs as biosensors for the detection of bioanalytes in tumor extract. In particular, we achieved the detection of exogenously added rabbit antigen in a much more complex environment, i.e. a human breast tumor extract. Our results show specific and high sensitive antigen detection with p-type SiNW-FETs in the range of 5-200 fM. Further and most importantly, the wires sense rabbit antigen molecules in the presence of a 100 000 mass excess of non-specific protein, indicating that the sensor is extremely resistant to noise.