| 초록 |
Graphene, two-dimensional sheet of sp2-hybridized carbon atoms, has received much attention in recent years for many applications such as field effect transistors, optoelectronic device, transparent conductive films, electromechanical resonators, energy storage and conversion, fuel cells, chemical & biological sensors due to its extraordinary mechanical, thermal, chemical, and optical properties. Label-free electrical detection of cancer biomarkers which can provide the point-of-care diagnostics with low-cost, high speed, low detection limit, large dynamic range, high specificity, and high sensitivity is of great importance for early diagnosis of cancer. Nanosensors with nanowire and carbon nano tube utilizing nanostructured semiconductors have shown the possibility of label-free, electrical, highly sensitive detection of disease biomarkers. Here we describe ultrahigh sensitive electrical detection of a cancer biomarker, prostate specific antigen/α1-antichymotrypsin (PSA-ACT) complex, using reduced graphene oxide (rGO)-field effect transistor (FET) in which sensing layer was simply formed by self-assembly of rGO nanosheets on aminated pattern generated by inkjet printing. The rGO FET sensor showed the precise shift of the Dirac point with the analyte concentration in wide range of linear response from 1 ng/ml to 1 fg/ml and extremely low detection limit as low as 1 fg/ml. Ease of fabrication and extremely high performance may enable graphene FET as versatile diagnostic nanosensors. |
