Nanowire Aptamer-Sensitized Biosensor Chips with Gas Plasma-Treated Surface for the Detection of Hepatitis C Virus Core Antigen

Abstract

Herein, we have demonstrated highly sensitive real-time biospecific detection of a protein marker of hepatitis C—the core antigen of hepatitis C virus (HCVcoreAg)—using a nanowire (NW) biosensor. The primary element of the NW-biosensor is a chip with p-type conductance, bearing silicon-on-insulator (SOI) nanowire structures on its surface. The nanowire structures are fabricated by gas-plasma treatment and electron beam lithography. The detection specificity was provided by sensitization of the sensor surface with aptamers against HCVcoreAg. The influence of buffer pH on the sensor response signal was studied. The effect of reverse polarity of the biosensor response signal with change from the acidic buffer pH to the neutral one was found. The lowest detectable HCVcoreAg concentration was determined to be 2.0 × 10−15 M in both acidic (pH 5.1) and neutral (pH 7.4) buffer solution. The proposed aptamer-sensitized sensor was also successfully applied to detect HCVcoreAg in serum samples of hepatitis C patients.

Raman Spectroscopy-Based Quality Control of “Silicon-On-Insulator” Nanowire Chips for the Detection of Brain Cancer-Associated MicroRNA in Plasma

“…To remove organic contaminants, the surface of the SOI-NW sensor chips was treated, as described elsewhere [ 32 , 41 , 42 ], with aqueous isopropanol solution, and then with a solution containing HF and ethanol (in order to remove the native oxide layer formed during the chip storage). After such a treatment, the chip was incubated in an ozonator (UV Ozone Cleaner–ProCleaner ™ Plus, BioForce Nanosciences, (Ossila Ltd., Sheffield, UK) in order to form hydroxyl groups on the SOI-NW surface, then it was silanized with APTES (as described in our previous papers [ 41 , 43 , 44 ]), washed with ethanol and dried [ 41 ].…”

“…Nanowire (NW) biosensors represent one of the types of molecular detectors. Their use for the highly sensitive detection of various biomolecules [32][33][34] and viral particles [35] was previously demonstrated in a number of papers. These biosensors allow for label-free detection of biological macromolecules in real time with high sensitivity (at femtomolar and even subfemtomolar level).…”

Optical Monitoring of the Production Quality of Si-Nanoribbon Chips Intended for the Detection of ASD-Associated Oligonucleotides

“…The layout and characteristics of Si-NR chips, employed herein, were described in detail in our previous papers [ 27 , 28 , 29 ].…”

“…Time dependencies of the current I ds ( t ) were recorded in real time at V g = 30 V and V ds = 0.2 V. The results obtained were presented in the form of I ds ( t ) curves, representing the differential signal between the working NR (with immobilized probe_1) and control NR (with immobilized probe_2). A detailed schematic of electrical signal processing has been presented in [ 27 ].…”

Highly Sensitive Detection of CA 125 Protein with the Use of an n-Type Nanowire Biosensor

“…The nanowire biosensor setup is described in detail in [ 19 ]. The electrical measurements were performed with a Keithley Model 6487 picoampermeter (Keithley, Solon, USA).…”