Experimental conditions: 1 mM potassium phosphate buffer, pH 7.4, 55 V, 0.1 V, solution volume in the cell 107 L; NR is usually sensitized with antibodies against influenza computer virus. buffer solutions at the target particles concentration within the range from 107 to 103 viral particles per milliliter (VP/mL). The lowest detectable concentration of the target viral particles was 6 10?16 M (corresponding to 104 VP/mL). The use of solutions made up of ~109 to 1010 VP/mL resulted in saturation of the sensor surface with the target virions. In the saturation mode, detection was impossible. family, and are divided into several typesA, B, C, and Dbased on antigen differences in Cipargamin the virions ribonucleoproteins, the latter not starting any inter-type serologic reactions, and defining the computer virus category. Seasonal epidemics are caused by influenza A and influenza B viruses. Virions of these viruses (with a diameter of 80C120 nm, though they are sometimes filamentous and reach a length of over 20 m) consist of a two-layer envelope and are covered by multiple transmembrane glycoproteinshemagglutinin (HA) and neuraminidase (NA), as well as by small (20C60 molecules/virion) Rabbit Polyclonal to hCG beta quantities of M2 protein. M1 membrane protein, being one of the most abundant proteins in a virion, connects to the lipid envelope to maintain virion morphology. A nucleocapsid inside the virion is usually created by eight fragments of single-stranded RNA, a nucleoprotein (N), and polymerase complex proteins (PA, PB1, and PB2) [3,4]. The number of copies of each protein can vary for different computer virus strains . To date, enzyme-linked immunosorbent assay (ELISA)-based, and polymerase chain reaction (PCR)-based methods have become popular in the laboratory diagnosis of influenza [5,6]. However, the analysis time required to obtain results using these methods, is usually 4 to 6 6 h, which is usually too long in the case of urgent anti-epidemic steps. Nanoribbon (NR) detector Cipargamin represents a molecular detector, which allows one to identify single biological macromolecules and viral particles  in the course of their counting, which defines the high speed and concentration sensitivity of analysis. The theory of operation of the NR detector is based on the registration of an electric current flowing through a NR. A viral particle (VP), upon its adsorption onto the NR surface, changes its conductivity. Chiang et al. , and Patolsky et al. , exhibited the detection of single virion avian influenza viruses at a concentration of 10?17 M, using a chip with silicon nanowire sensors. Cipargamin Shen F. et al. , employed a sensor chip, based on silicon nanoribbons, fabricated by chemical vapor deposition (CVD). With such a chip, these authors demonstrated the detection of influenza A viral particles at a concentration of 29 viruses/L (VP/L) Cipargamin in 100-fold diluted clinical exhaled breath condensate (EBC) samples . Once again, the authors of the above-mentioned papers used sensor chips of p-type conductance for the detection of target viral particles. Herein, we exhibited the use of sensor chips of n-type conductance for the detection of influenza computer virus particles. It should be emphasized that, in contrast to the above-cited works, our sensor chips are fabricated using a complementary metal-oxide-semiconductor (CMOS)-compatible technology, thus allowing simpler transition to their mass production. In our experiments, the lowest detectable concentration of the target viral particles amounted to 6 10?16 M (104 VP/mL). 2. Materials and Methods 2.1. Gear Nanoribbon detector (Russia), UV Ozone CleanerProCleaner? Plus (Ossila Ltd., Sheffield, UK), Piezorray micro-arraying system (PerkinElmer, Inc., Waltham, MA, USA), 10-channel data collection and storage system (Agama + JSC, Moscow, Russia). 2.2. Chemicals The cross-linking agent 3,3-dithiobis (sulfosuccinimidyl propionate) (DTSSP) was purchased from Pierce (Waltham, MA, USA). The following chemicals were also used: Potassium phosphate monobasic (KH2PO4), hydrofluoric (HF) acid, 96% ethanol (C2H5OH) (Reakhim, Moscow, Russia); 3-aminopropyltriethoxysilane (APTES) (Sigma Aldrich, St.-Louis, MO, USA); isopropanol 99.9% (C3H8O) (Acros Organics B.V.B.A., Geel, Belgium). Deionized water was obtained with a Simplicity UV purification system (Millipore, Molsheim, France). 2.3. Proteins and Viral Particles Murine monoclonal antibodies against hepatitis B computer virus antigen (HBsAg) (clone NF5), affinity purified.