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Biosensor Based on a Nanowire Field-effect Transistor for the Determination of Prostate Specific Antigen
Available online at www.sciencedirect.com
ScienceDirect Procedia Technology 27 (2017) 234 – 235
Biosensors 2016
Biosensor based on a nanowire field-effect transistor for the determination of prostate specific antigen Maya Rubtsovaa,*, Galina Presnovaa, Denis Presnovb,c, Vladimir Krupeninc, Vitaly Grigorenkoa, Alexey Egorova a Chemistry Faculty, M.V.Lomonosov Moscow State University, Leninskie gori, 119991 Moscow, Russia Skobeltsyn Institute of Nuclear Physics, M.V.Lomonosov Moscow State University, Leninskie gori, 119991 Moscow, Russia c Faculty of Physics, M.V.Lomonosov Moscow State University, Leninskie gori, 119991 Moscow, Russia
b
Abstract We report about a label-free and fast assay based on nanowire field-effect transistor (NW FET) for determination of PSA in human serum. Functionalization of NWs was performed by a new method using 5 nm gold nanoparticles (GNPs), which provides oriented covalent attachment of antibody half-fragments via their thiol groups. We use the GNPs to increase the effective surfaceto-volume ratio of the silicon nanowires, which resulted in higher sensitivity to pH and improved electrical performance of the biosensors. NW FETs demonstrated high sensitivity and the widest range of detectable PSA concentrations. The presented biosensor was applied to human serum samples with different PSA content, yielding promising results for use in real sample assessment. The sensitivity achieved by the biosensor was 2 orders of magnitude higher than the well-established ELISA method. ©2017 2016The TheAuthors. Authors. Published Elsevier © Published by by Elsevier Ltd.Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of Biosensors 2016. Peer-review under responsibility of the organizing committee of Biosensors 2016 Keywords: biosensor; nanowire field-effect transistor; prostate specific antitigen (PSA); gold nanoparticles; covalent immobilization
During the past decades semiconductor nanowire field-effect transistors (NWFETs) were attracted a particular attention due to unique electronic properties, ultra small dimensions and label-free detection of analytes in real-time mode [1, 2]. The aim of present study was to develop a new functionalization technique for silicon by small size gold nanoparticles (GNPs) for the improvement of NW FETs electrical performance. They were applied for the quantitative determination of prostate specific antigen (PSA), which is a molecular marker of prostate cancer.
* Corresponding author. Tel: +7495-9392727; Fax: +7495-9392742. E-mail address: [email protected]
2212-0173 © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of Biosensors 2016 doi:10.1016/j.protcy.2017.04.099
Maya Rubtsova et al. / Procedia Technology 27 (2017) 234 – 235
The transistors with nanowire channel were made of silicon on insulator (SOI) with Schottky contacts (Si-Ti) using high-resolution e-beam lithography, thin film vacuum deposition and reactive-ion etching processes eliminating complicated processes of doping and thermal annealing [3]. This allows us to simplify substantially the transistors manufacturing. In a comparison with traditional doped source and drain device structures the FETs with Schottky barriers have got certain important advantages: simple and low temperature fabricating process, lower leakage current and parasitic resistance at sub-100 nm range, elimination of doping or silicide formation and subsequent thermal annealing processes. Specific binding of antigen with monoclonal antibodies or their fragments immobilized on the nanowire surface leads to a transistor conductivity change in response to variations of electric field at the surface. The small size of nanodevices imposes certain requirements on the density and uniformity of the biorecognition layer. In order to achieve an optimal density and uniform distribution of chemical groups for the covalent attachment of antibodies the different approaches for modification of silicon supports were investigated: chemical modification by different organo-silanes; modification by small size GNPs of 5 nm. A new method for covalent immobilization of halffragments of antibodies on the silicon nanowires modified with 3-glycidopropyltriethoxysilane with thiol groups and 5 nm GNPs (Fig. 1 a and b) provides the high density of antibody active sites with favorable orientation and improved surface-to-volume ratio enhancing electrical performance of the transistor. NW FETs functionalized by GNPs showed extremely high pH sensitivity of 70 mV/pH. The total charge of a protein molecule and transistor conductivity change strongly depends on рН of the buffer. Signal inversion was detected at pH range of 6.8-7.5. The value of inversion matches the isoelectric point of PSA which is 7.5 [4]. At pH higher 7.5 the signal value increased slightly, while at low pH values there was a significant decrease in the response of the transistor. Binding of PSA with monoclonal antibodies on the NWs was registered at pH 8.0. The limit of PSA detection was of 23 fg/mL, concentration range of 23 fg/mL - 500 ng/mL (7 orders of magnitude) see Fig. 1(c). Response time was less than 5-10 sec, and analysis time per sample was 1 minute. The applicability of the method for PSA determination in human serum, diluted 100 times, was demonstrated. The results for quantitative PSA determination correlated well with the data of well-established ELISA method (the correlation coefficient was of 0.97).
Fig. 1. SEM images of NW FETs functionalized with 5 nm GNPs (a,b) and calibration curve for the detection of PSA in 0.01 x PBS buffer (c).
Acknowledgements The work was supported by the Russian Foundation for Basic Research (grants 13-04-01137 and 16-29-03266). References [1] Zhang A, Lieber CM. Nano-Bioelectronics. Chem Rev 2016; 116:215-257. [2] Noor MO, Krull UJ. Silicon nanowires as field-effect transducers for biosensor development: a review. Anal Chim Acta 2014; 825:1-25. [3] Presnov DE, Amitonov SV, Krutitskii PA, Kolybasova VV, Devyatov IA, Krupenin VA, Soloviev II. A highly pH-sensitive nanowire fieldeffect transistor based on silicon on insulator. Beilstein J Nanotechnol 2013; 4:330-335. [4] Huber PR, Schmid HP, Mattarelli G, Strittmatter B, van Steenbrugge GJ, Maurer A. Serum free prostate specific antigen: isoenzymes in benign hyperplasia and cancer of the prostate. Prostate 1995; 27:212-219.
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ScienceDirect Procedia Technology 27 (2017) 234 – 235
Biosensors 2016
Biosensor based on a nanowire field-effect transistor for the determination of prostate specific antigen Maya Rubtsovaa,*, Galina Presnovaa, Denis Presnovb,c, Vladimir Krupeninc, Vitaly Grigorenkoa, Alexey Egorova a Chemistry Faculty, M.V.Lomonosov Moscow State University, Leninskie gori, 119991 Moscow, Russia Skobeltsyn Institute of Nuclear Physics, M.V.Lomonosov Moscow State University, Leninskie gori, 119991 Moscow, Russia c Faculty of Physics, M.V.Lomonosov Moscow State University, Leninskie gori, 119991 Moscow, Russia
b
Abstract We report about a label-free and fast assay based on nanowire field-effect transistor (NW FET) for determination of PSA in human serum. Functionalization of NWs was performed by a new method using 5 nm gold nanoparticles (GNPs), which provides oriented covalent attachment of antibody half-fragments via their thiol groups. We use the GNPs to increase the effective surfaceto-volume ratio of the silicon nanowires, which resulted in higher sensitivity to pH and improved electrical performance of the biosensors. NW FETs demonstrated high sensitivity and the widest range of detectable PSA concentrations. The presented biosensor was applied to human serum samples with different PSA content, yielding promising results for use in real sample assessment. The sensitivity achieved by the biosensor was 2 orders of magnitude higher than the well-established ELISA method. ©2017 2016The TheAuthors. Authors. Published Elsevier © Published by by Elsevier Ltd.Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of Biosensors 2016. Peer-review under responsibility of the organizing committee of Biosensors 2016 Keywords: biosensor; nanowire field-effect transistor; prostate specific antitigen (PSA); gold nanoparticles; covalent immobilization
During the past decades semiconductor nanowire field-effect transistors (NWFETs) were attracted a particular attention due to unique electronic properties, ultra small dimensions and label-free detection of analytes in real-time mode [1, 2]. The aim of present study was to develop a new functionalization technique for silicon by small size gold nanoparticles (GNPs) for the improvement of NW FETs electrical performance. They were applied for the quantitative determination of prostate specific antigen (PSA), which is a molecular marker of prostate cancer.
* Corresponding author. Tel: +7495-9392727; Fax: +7495-9392742. E-mail address: [email protected]
2212-0173 © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of Biosensors 2016 doi:10.1016/j.protcy.2017.04.099
Maya Rubtsova et al. / Procedia Technology 27 (2017) 234 – 235
The transistors with nanowire channel were made of silicon on insulator (SOI) with Schottky contacts (Si-Ti) using high-resolution e-beam lithography, thin film vacuum deposition and reactive-ion etching processes eliminating complicated processes of doping and thermal annealing [3]. This allows us to simplify substantially the transistors manufacturing. In a comparison with traditional doped source and drain device structures the FETs with Schottky barriers have got certain important advantages: simple and low temperature fabricating process, lower leakage current and parasitic resistance at sub-100 nm range, elimination of doping or silicide formation and subsequent thermal annealing processes. Specific binding of antigen with monoclonal antibodies or their fragments immobilized on the nanowire surface leads to a transistor conductivity change in response to variations of electric field at the surface. The small size of nanodevices imposes certain requirements on the density and uniformity of the biorecognition layer. In order to achieve an optimal density and uniform distribution of chemical groups for the covalent attachment of antibodies the different approaches for modification of silicon supports were investigated: chemical modification by different organo-silanes; modification by small size GNPs of 5 nm. A new method for covalent immobilization of halffragments of antibodies on the silicon nanowires modified with 3-glycidopropyltriethoxysilane with thiol groups and 5 nm GNPs (Fig. 1 a and b) provides the high density of antibody active sites with favorable orientation and improved surface-to-volume ratio enhancing electrical performance of the transistor. NW FETs functionalized by GNPs showed extremely high pH sensitivity of 70 mV/pH. The total charge of a protein molecule and transistor conductivity change strongly depends on рН of the buffer. Signal inversion was detected at pH range of 6.8-7.5. The value of inversion matches the isoelectric point of PSA which is 7.5 [4]. At pH higher 7.5 the signal value increased slightly, while at low pH values there was a significant decrease in the response of the transistor. Binding of PSA with monoclonal antibodies on the NWs was registered at pH 8.0. The limit of PSA detection was of 23 fg/mL, concentration range of 23 fg/mL - 500 ng/mL (7 orders of magnitude) see Fig. 1(c). Response time was less than 5-10 sec, and analysis time per sample was 1 minute. The applicability of the method for PSA determination in human serum, diluted 100 times, was demonstrated. The results for quantitative PSA determination correlated well with the data of well-established ELISA method (the correlation coefficient was of 0.97).
Fig. 1. SEM images of NW FETs functionalized with 5 nm GNPs (a,b) and calibration curve for the detection of PSA in 0.01 x PBS buffer (c).
Acknowledgements The work was supported by the Russian Foundation for Basic Research (grants 13-04-01137 and 16-29-03266). References [1] Zhang A, Lieber CM. Nano-Bioelectronics. Chem Rev 2016; 116:215-257. [2] Noor MO, Krull UJ. Silicon nanowires as field-effect transducers for biosensor development: a review. Anal Chim Acta 2014; 825:1-25. [3] Presnov DE, Amitonov SV, Krutitskii PA, Kolybasova VV, Devyatov IA, Krupenin VA, Soloviev II. A highly pH-sensitive nanowire fieldeffect transistor based on silicon on insulator. Beilstein J Nanotechnol 2013; 4:330-335. [4] Huber PR, Schmid HP, Mattarelli G, Strittmatter B, van Steenbrugge GJ, Maurer A. Serum free prostate specific antigen: isoenzymes in benign hyperplasia and cancer of the prostate. Prostate 1995; 27:212-219.
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