Design and facile synthesis of mesoporous cobalt nitride nanosheets modified by pyrolytic carbon for the nonenzymatic glucose detection

In this paper, we have designed and facilely synthesized the novel mesoporous cobalt nitride nanosheets modified by the pyrolytic carbon conductor (denoted as Co2N0.67 NSs). By the hydrothermal method, we successfully grown the precursor nanosheets (i.e. Co(OH)(2) NSs) under the regulate and control of hexamethylenetetramine (HMT) weak base. Through a simple nitridation process in NH3 atmosphere at 400W degrees C, the as-prepared smooth Co(OH)(2) NSs were thoroughly transformed into the mesoporous Co2N0.67 NSs modified by pyrolytic carbon of HMT. Thanks to a synergistic effect between the metallic character of Co2N0.67 phase and good electroconductibility of carbon, the as-prepared hybrid Co2N0.67 NSs can boost electron transfer from catalyst surfaces and then form abundant Co4+ active sites on electrode surfaces in electrochemical reaction processes. Meanwhile, vast mesoporous structures appeared in Co(2)N(0.6)7 NSs further promoted the dispersion of Co4+ active sites and enhanced the mass transfer rate. Benefitting from the above mentioned factors, Co2N0.67 NSs therefore exhibit excellent glucose oxidation ability than another two control samples (i.e. Co(OH)(2) NSs and Co3O4 NSs). When used for glucose detection after the electrochemical activation process, the optimal Co2N0.67 NSs display excellent detection parameters: a wide linear range of 0.01-8.0 mM, a large sensitivity of 921.18 uA cm(-2)mM(-1) glucose, a low detection limit of 0.1 mu M, a response time within 3 s, good reproducibility, considerable long-term stability, and excellent anti-interference to electroactive molecules and Cl-. Upon utilized for measuring glucose concentrations in serum samples, the detection results on Co2N0.67 NSs are similarly satisfying and accurate. This work opens a new possibility for the sensitive and fast glucose concentration detection in human blood serum samples. (C) 2017 Elsevier B. V. All rights reserved.