title: Enhanced photoelectrochemical immunosensing of cardiac troponin I based on energy transfer between N-acetyl-L-cysteine capped CdAgTe quantum dots and dodecahedral Au nanoparticles.
abstract: An immunosensor was fabricated with an immobilized antibody for cardiac troponin I (anti-cTnI) on a photoresponsive composite material consisting of N-acetyl-L-cysteine capped CdAgTe quantum dots (NAC-CdAgTe QDs) and dodecahedral gold nanoparticles (AuNPs) stabilized by 1-(10-bromodecyl)-3-methylimidazolium bromide ionic liquid. Synthesized materials were characterized by TEM, SEM, UV-Vis, XRD, XPS, EIS, fluorescence, and photoelectrochemical method to confirm their morphology, elemental composition, and properties. The sensing element, anti-cTnI, was then covalently bound to the composite material coated on a glassy carbon electrode to complete the immunosensor, abbreviated as anti-cTnI(BSA)/NAC-CdAgTe QDs/AuNPs/GCE. Photocurrent was measured when the sensor was excited by a 405nm 100mW laser light. Optimal operating conditions, stability, reversibility, and reproducibility of the sensor have been studied. Performance of the aforementioned sensor was monitored with the photocurrent and the relative photocurrent variation, which is expressed as the changes in photocurrent upon the formation of antibody-antigen complex relative to the initial current measured in the unbound state of antibody. The experiment showed the relative photocurrent variation is directly proportional to the logarithm of cTnI concentration between 5.0pgmL-1and 20.0ngmL-1with a detection limit of 1.756pgmL-1(S/N=3). Performance of the immunosensor in common interferents and clinical human serum samples was investigated, showing comparable to ELISA with good selectivity, accuracy, and precision.
authors.affiliation: Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tan
authors.affiliation: Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. Electronic address: wangyychem@126.com.
authors.forename: Yanying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.
authors.forename: Mingshi
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Ye
authors.affiliation: Department of Chemistry, University of Wisconsin-Platteville, 1 University Plaza, Platteville, WI 53818-3099, USA.
authors.forename: Tsunghsueh
authors.initials: T
authors.lastname: Wu
authors.affiliation: Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. Electronic address: lichychem@163.com.
authors.forename: Chunya
authors.initials: C
authors.lastname: Li
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry*; D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002104:Cadmium / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods; D004735:Energy Transfer; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008027:Light; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012834:Silver / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry; D019210:Troponin I / Q000097:blood*
chemical_list: D055910:Antibodies, Immobilized; D019210:Troponin I; D002104:Cadmium; D012834:Silver; D006046:Gold; D013691:Tellurium; D000111:Acetylcysteine
keywords: Au nanoparticles; Cardiac troponin I; CdAgTe; Energy transfer; Immunosensor; Photoelectrochemistry