{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T11:34:30Z","timestamp":1784633670939,"version":"3.55.0"},"reference-count":43,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2017,11,10]],"date-time":"2017-11-10T00:00:00Z","timestamp":1510272000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We have developed a novel mediated biochemical oxygen demand (BOD) biosensor based on immobilized Bacillus subtilis (B. subtilis) on three-dimensional (3D) porous graphene-polypyrrole (rGO-PPy) composite. The 3D porous rGO-PPy composite was prepared using hydrothermal method following with electropolymerization. Then the 3D porous rGO-PPy composite was used as a support for immobilizing negatively charged B. subtilis denoted as rGO-PPy-B through coordination and electrostatic interaction. Further, the prepared rGO-PPy-B was used as a microbial biofilm for establishing a mediated BOD biosensor with ferricyanide as an electronic acceptor. The indirect determination of BOD was performed by electrochemical measuring ferrocyanide generated from a reduced ferricyanide mediator using interdigited ultramicroelectrode array (IUDA) as the working electrode. The experimental results suggested a good linear relationship between the amperometric responses and BOD standard concentrations from 4 to 60 mg\/L, with a limit detection of 1.8 mg\/L (S\/N \u2265 3). The electrochemical measurement of real water samples showed a good agreement with the conventional BOD5 method, and the good anti-interference as well as the long-term stability were well demonstrated, indicating that the proposed mediated BOD biosensor in this study holds a potential practical application of real water monitoring.<\/jats:p>","DOI":"10.3390\/s17112594","type":"journal-article","created":{"date-parts":[[2017,11,10]],"date-time":"2017-11-10T11:12:26Z","timestamp":1510312346000},"page":"2594","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":43,"title":["A Mediated BOD Biosensor Based on Immobilized B. Subtilis on Three-Dimensional Porous Graphene-Polypyrrole Composite"],"prefix":"10.3390","volume":"17","author":[{"given":"Jingfang","family":"Hu","sequence":"first","affiliation":[{"name":"Key Laboratory of Sensor, Beijing Information Science and Technology University, Beijing 100000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yueqi","family":"Li","sequence":"additional","affiliation":[{"name":"Key Laboratory of Sensor, Beijing Information Science and Technology University, Beijing 100000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guowei","family":"Gao","sequence":"additional","affiliation":[{"name":"Key Laboratory of Sensor, Beijing Information Science and Technology University, Beijing 100000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shanhong","family":"Xia","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Science, Beijing 100000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,11,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"8333","DOI":"10.1007\/s11356-014-2841-8","article-title":"Electrochemical advanced oxidation technologies for removal of organic pollutants from water","volume":"21","author":"Oturan","year":"2014","journal-title":"Environ. 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