Thin Film Polycrystalline Silicon Nanowire Biosensors

Abstract

Polysilicon nanowire biosensors have been fabricated using a top-down process and were used to determine the binding constant of two inflammatory biomarkers. A very low cost nanofabrication process was developed, based on simple and mature photolithography, thin film technology, and plasma etching, enabling an easy route to mass manufacture. Antibody-functionalized nanowire sensors were used to detect the proteins interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) over a wide range of concentrations, demonstrating excellent sensitivity and selectivity, exemplified by a detection sensitivity of 10 fM in the presence of a 100 000-fold excess of a nontarget protein. Nanowire titration curves gave antibody−antigen dissociation constants in good agreement with low-salt enzyme-linked immunosorbent assays (ELISAs). This fabrication process produces high-quality nanowires that are suitable for low-cost mass production, providing a realistic route to the realization of disposable nanoelectronic point-of-care (PoC) devices.

Grain size tuning of nanostructured Cu2O films through vapour phase supersaturation control and their characterization for practical applications

“…Nanostructured semiconductor films composed of thin layers of nanostructured objects such as nanoparticles, nanorods, nanowires or nanoporous networks with variable grain size and controlled porosity can exhibit properties superior to conventional thin films due to the deliberate engineering of nanoscale features into their structure and these films have practical applications in areas such as photovoltaics, electrochemical sensors, photoelectrochemical water splitting, biosensors and as antireflection layers. [1][2][3][4][5] Techniques such as thermal evaporation, 6 pulsed laser deposition, 7 DC and RF sputtering, 8,9 plasma evaporatihon, 10 sol-gel technique, 11 molecular beam epitaxy, 12 electrodeposition 13 and chemical vapor deposition 14 have been employed for the synthesis of nanostructured thin films of different semiconductors. Another technologically logical strategy for creating nanostructured films is the alignment of nanoparticle building blocks into ordered superstructures with non-resistive inter-particle contacts by bottom-up approaches and is one of the recent key topics in the area of nanomaterials.…”

Low-cost top-down zinc oxide nanowire sensors through a highly transferable ion beam etching for healthcare applications

“…However, when compared to conventional ISFETs, top-down silicon nanowires require costly e-beam or deep UV lithography and Silicon-on-Insulator (SOI) substrates [6,7]. To significantly reduce the fabrication cost, we have proposed a thin-film technology (TFT) alternative using polysilicon nanowires formed by reactive-ion etching (RIE) through a spacer etch technology [8]. However, the formation of polysilicon and gate dielectrics require high temperature processes such as silicon recrystallization and thermal oxidation.…”

Three-Mask Polysilicon Thin-Film Transistor Biosensor

“…Several groups [13]- [16] have reported top-down approaches for the fabrication of polysilicon nanowires using variants of thin film transistor technology. In our previous work [15] we reported a technology for producing rectangular polysilicon nanowire biosensors and demonstrated the detection of two inflammatory biomarkers, the proteins interleukin-8 and tumor necrosis factor-alpha, over a wide range of concentrations and with excellent sensitivity.…”