Construction of label-free electrochemical immunosensor on mesoporous carbon nanospheres for breast cancer susceptibility gene Fan, Haixia; Zhang, Yong; Wu, Dan; Ma, Hongmin; Li, Xiaojing; Li, Yan; Wang, Huan; Li, He; Du, Bin [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)]; Wei, Qin [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)] 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ADSORPTION; AMPEROMETRY; CARBON; DETECTION; FILMS; MAMMARY GLANDS; MOLTEN SALTS; NANOSTRUCTURES; NEOPLASMS; SENSITIVITY; STABILITY; SURFACE AREA; SURFACES; TOLUIDINE BLUE Highlights: ► The immunosensor is designed to determine breast cancer susceptibility gene. ► Mesoporous carbon nanospheres (MCN) have great adsorption capacity. ► MCN could enhance the electroactivity of toluidine blue. ► Room temperature ionic liquid should increase the electrochemical signal. -- Abstract: In this contribution, mesoporous carbon nanospheres (MCN) were used to fabricate a label-free electrochemical immunosensor for breast cancer susceptibility gene (BRCAl). The detection platform was constructed by conjugation of anti-BRCA1 on glassy carbon electrodes which were modified by mesoporous carbon nanospheres–toluidine blue nanocomposite (MCN–TB)/room temperature ionic-liquid (RTIL) composited film. TB was adsorbed onto MCN and acted as a redox probe. The electroactivity of TB was greatly enhanced in the presence of MCN. The good conductivity of MCN and BMIM·BF{sub 4} could promote the electron transfer and thus enhance the detection sensitivity. Moreover, the large surface area of MCN and the protein-binding properties of BMIM·BF{sub 4} could greatly increase the antibody loading. The specific antibody–antigen immunoreaction on the electrode surface resulted in a decrease of amperometric signal of the electrode. Under optimized conditions, the amperometric signal decreased linearly with BRCAl concentration in the range of 0.01–15 ng mL{sup −1} with a low detection limit of 3.97 pg mL{sup −1}. The immunosensor exhibits high sensitivity, good selectivity and stability. Available from http://dx.doi.org/10.1016/j.aca.2013.01.066 Netherlands 2013-04-03 English Journal Article Journal Name: Analytica Chimica Acta; Journal Volume: 770; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA) Medium: X; Size: page(s) 62-67 https://doi.org/10.1016/J.ACA.2013.01.066 PII: S0003-2670(13)00215-8 [] 770 Journal ID: ISSN 0003-2670; CODEN: ACACAM; Other: PII: S0003-2670(13)00215-8; TRN: NL14R0017040659 NLN 2014-04-28 22219704