Detection of clinically relevant levels of protein analyte under physiologic buffer using planar field effect transistors.
Electrochemical detection of protein binding at physiological salt concentration by planar field effect transistor platforms has yet to be documented convincingly. Here we report detection of streptavidin and clinically relevant levels of biotinylated monokine induced by interferon gamma (MIG) at physiological salt concentrations with AlGaN heterojunction field effect transistors (HFETs). The AlGaN HFETs are functionalized with a silane linker and analyte-specific affinity elements. Polarity of sensor responses is as expected from n-type HFETs to negatively and positively charged analytes. Sensitivity of the HFET sensors increases when salt concentration decreases, and the devices also exhibit dose-dependent responses to analyte. Detection of clinically relevant MIG concentrations at physiological salt levels demonstrates the potential for AlGaN devices to be used in development of in vivo biosensors.
Gupta
Samit
S
The Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA.
Elias
Mark
M
Wen
Xuejin
X
Shapiro
John
J
Brillson
Leonard
L
Lu
Wu
W
Lee
Stephen Craig
SC
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D054370:Chemokine CXCL9 / Q000032:analysis* / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D008839:Microelectrodes; D025941:Protein Interaction Mapping / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019809:Streptavidin / Q000032:analysis* / Q000737:chemistry; D014173:Transistors, Electronic
D054370:Chemokine CXCL9; D019809:Streptavidin