title: CMOS-compatible, label-free silicon-nanowire biosensors to detect cardiac troponin I for acute myocardial infarction diagnosis.
abstract: A label-free biosensor for electrical detection of cardiac troponin I (cTnI), a highly sensitive and selective biomarker of acute myocardial infarction (AMI), is demonstrated using silicon nanowire (SiNW) based field-effect transistors (FETs). The FET devices were fabricated by a complementary metal oxide semiconductor (CMOS) compatible top-down approach to define the SiNW followed by tetramethylammonium hydroxide (TMAH) wet etching. Electrical characterizations of the SiNW FET revealed an ambipolar conduction characteristic with an on/off ratio of 10(5)-10(6). CTnI monoclonal antibodies were then covalently immobilized on the SiNW surfaces. By integrating with a homemade biosensor measurement system, the biosensor exhibited rapid and sensitive response to cTnI proteins. The current response showed a nature of logarithm relationship against the cTnI concentration from 46 ng/mL down to 0.092 ng/mL. Moreover, an anti-interference capability of the fabricated biosensor was also assessed. By utilizing the top-down fabrication method, this work provides an efficient way for the cTnI proteins detection with an enormous potential of mass-production, which definitely facilitate the practical applications.
authors.affiliation: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou Industrial Park, Jiangsu, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Kong
authors.forename: Ruigong
authors.initials: R
authors.lastname: Su
authors.forename: Beibei
authors.initials: B
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Guosheng
authors.initials: G
authors.lastname: Cheng
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D009203:Myocardial Infarction / Q000175:diagnosis*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D053770:Nanowires / Q000737:chemistry; D012828:Silicones / Q000737:chemistry; D014173:Transistors, Electronic; D019210:Troponin I / Q000302:isolation & purification*
chemical_list: D012828:Silicones; D019210:Troponin I