title: Biosensor based on a silicon nanowire field-effect transistor functionalized by gold nanoparticles for the highly sensitive determination of prostate specific antigen.
abstract: We have demonstrated label-free and real-time detection of prostate specific antigen (PSA) in human serum using silicon nanowire field effect transistors (NW FETs) with Schottky contacts (Si-Ti). The NW FETs were fabricated from SOI material using high-resolution e-beam lithography, thin film vacuum deposition and reactive-ion etching processes eliminating complicated processes of doping and thermal annealing. This allowed substantial simplifying the transistors manufacturing. A new method for covalent immobilization of half-fragments of antibodies on silicon modified by 3-glycidopropyltrimethoxysilane with thiol groups and 5nm gold nanoparticles (GNPs) was established. NW FETs functionalized by GNPs revealed extremely high pH sensitivity of 70mV/pH and enhanced electrical performance in the detection of antigen due to enhanced surface/volume ratio, favorable orientation of antibody active sites and approaching the source of the electric field close to the transistor surface. Si NWFETs were applied for quantitative detection of PSA in a buffer and human serum diluted 1/100. Response time was about 5-10s, and analysis time per sample was 1min. The limit of PSA detection was of 23fg/mL, concentration range of 23fg/mL-500ng/mL (7 orders of magnitude). The PSA concentrations determined by the NW FETs in serum were compared with well-established ELISA method. The results matched well with the correlation coefficient of 0.97.
authors: Chemistry Faculty, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Galina
authors: G
authors: Presnova
authors: Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia; Faculty of Physics, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Denis
authors: D
authors: Presnov
authors: Faculty of Physics, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Vladimir
authors: V
authors: Krupenin
authors: Chemistry Faculty, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Vitaly
authors: V
authors: Grigorenko
authors: Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia; Faculty of Physics, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Artem
authors: A
authors: Trifonov
authors: Chemistry Faculty, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Irina
authors: I
authors: Andreeva
authors: Chemistry Faculty, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Olga
authors: O
authors: Ignatenko
authors: Chemistry Faculty, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia.
authors: Alexey
authors: A
authors: Egorov
authors: Chemistry Faculty, M.V. Lomonosov Moscow State University, Leninskie gori, Moscow, 119991 Russia. Electronic address: mrubtsova@gmail.com.
authors: Maya
authors: M
authors: Rubtsova
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D017430:Prostate-Specific Antigen / Q000097:blood*; D012825:Silicon / Q000737:chemistry*; D014173:Transistors, Electronic
chemical_list: D055910:Antibodies, Immobilized; D006046:Gold; D017430:Prostate-Specific Antigen; D012825:Silicon
keywords: Antibodies; Biosensor; Covalent immobilization; Gold nanoparticles; Prostate specific antitigen (PSA); Silicon nanowire field-effect transistor