caa a22 4500 445879637 CHVBK 20180317145538.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s00604-010-0515-x doi (NATIONALLICENCE)springer-10.1007/s00604-010-0515-x Direct electrochemistry and enhanced electrocatalytic activity of hemoglobin entrapped in graphene and ZnO nanosphere composite film [Elektronische Daten] [Jing Xu, Changhua Liu, Zongfang Wu] A biocomposite film for sensing hydrogen peroxide (HP) is described that is based on nanospheres made from hemoglobin (Hb), graphene, and zinc oxide. The composition, morphology and size of the film were studied by transmission electron microscopy. UV-vis spectroscopy revealed that the Hb entrapped in the graphene and ZnO nanosphere retains its native structure. A pair of stable and well-defined quasi-reversible redox peaks of Hb was obtained, with a formal potential of −30mV at pH 6.5. Hb exhibits excellent long-term bioelectrocatalytic activity towards HP. The apparent heterogeneous electron transfer rate constant is 1.0s−1, indicating that the presence of graphene in the composite film facilitates the electron transfer between matrix and the electroactive center of Hb. The sensor responds linearly to HP in the range from 1.8μM to 2.3mM, with a detection limit of 0.6μM (at S/N = 3). The apparent Michaelis-Menten constant is 1.46mM. The biosensor displays high sensitivity, good reproducibility, and long-term stability. Figure TEM images of graphene insert: graphene-ZnO nanosphere Springer-Verlag, 2010 Graphene nationallicence ZnO nanosphere nationallicence Biosensor nationallicence Direct electron transfer nationallicence Hemoglobin nationallicence Xu Jing Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, 400700, Chongqing, People's Republic of China aut Liu Changhua Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, 400700, Chongqing, People's Republic of China aut Wu Zongfang Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, 400700, Chongqing, People's Republic of China aut Microchimica Acta Springer Vienna 172/3-4(2011-03-01), 425-430 0026-3672 172:3-4<425 2011 172 604 https://doi.org/10.1007/s00604-010-0515-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00604-010-0515-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Xu Jing Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, 400700, Chongqing, People's Republic of China aut NATIONALLICENCE 700 1- Liu Changhua Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, 400700, Chongqing, People's Republic of China aut NATIONALLICENCE 700 1- Wu Zongfang Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, 400700, Chongqing, People's Republic of China aut NATIONALLICENCE 773 0- Microchimica Acta Springer Vienna 172/3-4(2011-03-01), 425-430 0026-3672 172:3-4<425 2011 172 604 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer