An enhancement of high-k/oxide stacked dielectric structure for silicon-based multi-nanowire biosensor in cardiac troponin I detection

In this study, we demonstrate a series of multi-channel silicon nanowire (Si-NW) biosensors coated with different high-k dielectric materials for sensing property improvements. To enhance the compatibility to 3-Aminopropyltriethoxysilane (APTES) without any harsh surface treatment, a stacked structure of high-k dielectrics with ultrathin SiO2 is developed. Fluorescent experiments are employed to verify the enhancement. To experimentally examine the improvement of implemented devices, in addition, an acute myocradial infarction biomarker, cardiac troponin I (cTnI), with different concentrations is used. Based on the experimental results of ultrathin SiO2 sensing membrane structures stacked with 14 nm Al2O3 and 10 nm HfO2, compared with only high-k dielectric devices, the sensing property can be enhanced by 3.8 and 1.4 times, respectively. For the detection of lowest concentration, i.e. 320 fM, the signal enhancement is 20%. Based on this work, the proposed SiO2/high-k structure for Si-NW biosensor can be experimentally demonstrates a good potential for future applications in cTnI detections. (C) 2015 Elsevier B.V. All rights reserved.