Top-down Fabricated Polysilicon Nanoribbon Biosensor Chips for Cancer Diagnosis
- PDF / 313,100 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 51 Downloads / 163 Views
Top-down Fabricated Polysilicon Nanoribbon Biosensor Chips for Cancer Diagnosis Hsiao-Kang Chang1, Xiaoli Wang1, Noppadol Aroonyadet1, Rui Zhang2, Yan Song2, Ram Datar3, Richard Cote3, Mark Thompson2 and Chongwu Zhou1 1
Department of Electrical Engineering and 2Chemistry, University of Southern California, Los Angeles, CA 90089, U.S.A. 3 Department of Pathology, University of Miami, Miami, Florida 33136, U.S.A. ABSTRACT Nanobiosensors have drawn significant research interest in recent years owing to the advantages of label-free, electrical detection. However, nanobiosensors fabricated by bottom-up process are limited in terms of yield and device uniformity due to the challenges in assembly. Nanobiosensors fabricated by top-down process, on the other hand, exhibit better uniformity but require time and costly processes and materials to achieve the critical dimensions required for high sensitivity. In this report, we introduce a top-down nanobiosensor based on polysilicon nanoribbon. The polysilicon nanoribbon devices can be fabricated by conventional photolithography with only materials and equipments used in the standard CMOS process, thus resulting in great time and cost efficiency, as well as scalability. The devices show great response to pH changes with a wide dynamic range and high sensitivity. Biomarker detection is also demonstrated with clinically relevant sensitivity. Such results suggest that polysilicon nanoribbon devices exhibit great potential toward a highly efficient, reliable and sensitive biosensing platform. INTRODUCTION In recent years label-free, electrical nanobiosensors have drawn lots of research interests due to the potential of achieving superior time and cost efficiency to current state-of-the-art biosensing platform such as ELISA. Among nanobiosensors studied by various research teams, most of them are fabricated by “bottom-up” technique [1-4], that is, nanostructures are assembled to make devices. One of the major challenges for nanosensors fabricated by bottomup technique is assembly, which can significantly limit the yield and uniformity of such nanosensors. The yield is highly related to cost and throughput, and uniformity is essential to the reliability of nanobiosensors. Although intensive research efforts have been made toward assembly of nanostructures, most of the techniques still lack controllability, reproducibility and scalability. The other school of process in nanotechnology is “top-down” fabrication, which seeks to create nanoscale devices by using larger, externally-controlled ones to direct their assembly. Top-down fabrication is much more controllable than their bottom-up counterpart, thus leads to more uniform device performance. As a result, nanobiosensors fabricated using topdown approaches can yield more reliable diagnosis. One of the major challenges for top-down nanobiosensors, however, is to achieve large surface-to-volume ratio, as surface-to-volume ratio is directly linked to sensitivity. Research efforts have been made toward reducing the critical dimension of
Data Loading...
