Detection of oxidized low density lipoproteins by indium oxide nanowires-based field effect transistor

Oxidized low density lipoprotein (oxLDL) particles are known to initiate the development of coronary artery disease. Field effect transistors (FET) made of indium oxide (In/sub 2/O/sub 3/) nanowires have been demonstrated as sensitive chemical sensors for gaseous molecules such as NO/sub 2/ and NH/sub 3/. We hereby, apply In/sub 2/O/sub 3/ nanowires FETs to differentiate oxLDL from native LDL (nLDL), cytochrome-c and bovine serum albumin in terms of the transistor characteristic curves: I/sub D/-V/sub DS/ (current versus drain-source voltage) and I/sub D/-V/sub GS/ (current versus gate-source voltage). Measurements under static and flow conditions revealed that exposure of nanowires to these redox proteins selectively changed the FET conductivity and the gating effect of the transistors. To enhance the selectivity for oxLDL detection, surface chemistry modification with antioxLDL antibody was performed.