Label-Free, Electrical Detection of the SARS Virus N-Protein with Nanowire Biosensors Utilizing Antibody Mimics as Capture Probes

Abstract

Antibody mimic proteins (AMPs) are poly-peptides that bind to their target analytes with high affinity and specificity, just like conventional antibodies, but are much smaller in size (2-5 nm, less than 10kDa). In this report, we describe the first application of AMP in the field of nanobiosensors. In 2 O 3 nanowire based biosensors have been configured with an AMP (Fibronectin, Fn) to detect nucleocapsid (N) protein, a biomarker for severe acute respiratory syndrome (SARS). Using these devices, N protein was detected at sub-nanomolar concentration in the presence of 44 µM bovine serum albumin as a background. Furthermore, the binding constant of the AMP to Fn was determined from the concentration dependence of the response of our biosensors.

Label-Free Aptamer-Based Immunoglobulin Sensors Using Graphene Field-Effect Transistors

“…Siliconnanowire 1,2) and carbon-nanotube (CNT)-based biosensors [3][4][5][6][7][8] have been reported by many researchers over the past decade. In particular, the CNT is one of the strongest candidates for highly sensitive biological sensors owing to its large surface-to-volume ratio.…”

“…This indicates that the electrical characteristics of CNT fieldeffect transistors in a buffer solution are susceptible to noise. 10) Recently, network CNTs 3,8) or aligned CNT 11) devices have been investigated for the sensors to solve these problems. However, it is difficult to grow only semiconducting CNTs at present.…”

Bioaffinity detection of pathogens on surfaces

“…As shown in Figure 6, the charge transfer resistances associated 16 with the mass transfer of SEB complexed with the anti-SEB on the nanowire electrode proportionally increased with the SEB concentration. The In 2 O 3 nanowire FETs sensing platform was further developed for the detection of severe acute respiratory syndrome (SARS) virus by means of measuring the interaction of a biomarker associated with the SARS corona virus with the antibody mimic proteins immobilized on the nanowire surface [53].…”

“Bio-functionalization study of Memristive-Biosensors for early detection of prostate cancer”

“…Semiconductor nanowires and semiconducting carbon nanotubes are reported as promising building blocks for biosensors, enabling direct electrical detection of biomolecules and fast, low-cost analysis of biological processes [1][2][3][4][5][6]. Thanks to the high surface-to-volume ratio that the nanowire structures present, their electrical properties are strongly influenced by minor perturbations [7,8].…”