{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T12:20:36Z","timestamp":1782217236058,"version":"3.54.5"},"reference-count":37,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,12,29]],"date-time":"2020-12-29T00:00:00Z","timestamp":1609200000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Romanian Ministery of Research and Innovation, CCCDI-UEFISCDI","award":["project no. PN-III-P1-1.2-PCCDI-2017-0350 \/ 01.03.2018 (Graphene4Life), within PNCDI III"],"award-info":[{"award-number":["project no. PN-III-P1-1.2-PCCDI-2017-0350 \/ 01.03.2018 (Graphene4Life), within PNCDI III"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Multifunctional Bi- and Fe-modified carbon xerogel composites (CXBiFe), with different Fe concentrations, were obtained by a resorcinol\u2013formaldehyde sol\u2013gel method, followed by drying in ambient conditions and pyrolysis treatment. The morphological and structural characterization performed by X-ray diffraction (XRD), Raman spectroscopy, N2 adsorption\/desorption porosimetry, scanning electron microscopy (SEM) and scanning\/transmission electron microscopy (STEM) analyses, indicates the formation of carbon-based nanocomposites with integrated Bi and Fe oxide nanoparticles. At higher Fe concentrations, Bi-Fe-O interactions lead to the formation of hybrid nanostructures and off-stoichiometric Bi2Fe4O9 mullite-like structures together with an excess of iron oxide nanoparticles. To examine the effect of the Fe content on the electrochemical performance of the CXBiFe composites, the obtained powders were initially dispersed in a chitosan solution and applied on the surface of glassy carbon electrodes. Then, the multifunctional character of the CXBiFe systems is assessed by involving the obtained modified electrodes for the detection of different analytes, such as biomarkers (hydrogen peroxide) and heavy metal ions (i.e., Pb2+). The achieved results indicate a drop in the detection limit for H2O2 as Fe content increases. Even though the current results suggest that the surface modifications of the Bi phase with Fe and O impurities lower Pb2+ detection efficiencies, Pb2+ sensing well below the admitted concentrations for drinkable water is also noticed.<\/jats:p>","DOI":"10.3390\/molecules26010117","type":"journal-article","created":{"date-parts":[[2020,12,29]],"date-time":"2020-12-29T19:55:25Z","timestamp":1609271725000},"page":"117","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Carbon Xerogel Nanostructures with Integrated Bi and Fe Components for Hydrogen Peroxide and Heavy Metal Detection"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4675-7602","authenticated-orcid":false,"given":"Carmen I.","family":"Fort","sequence":"first","affiliation":[{"name":"Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, \u201cBabes-Bolyai\u201d University, Arany Janos 11, RO-400028 Cluj-Napoca, Romania"},{"name":"Laboratory of Advanced Materials and Applied Technologies, Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6760-7320","authenticated-orcid":false,"given":"Mihai M.","family":"Rusu","sequence":"additional","affiliation":[{"name":"Laboratory of Advanced Materials and Applied Technologies, Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"},{"name":"Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, \u201cBabes-Bolyai\u201d University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania"},{"name":"Nanostructured Materials and Bio-Nano-Interfaces Center, Institute of Interdisciplinary Research in Bio-Nano-Sciences, \u201cBabes-Bolyai\u201d University, T. Laurean 42, RO-400271 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liviu C.","family":"Cotet","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, \u201cBabes-Bolyai\u201d University, Arany Janos 11, RO-400028 Cluj-Napoca, Romania"},{"name":"Laboratory of Advanced Materials and Applied Technologies, Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adriana","family":"Vulpoi","sequence":"additional","affiliation":[{"name":"Nanostructured Materials and Bio-Nano-Interfaces Center, Institute of Interdisciplinary Research in Bio-Nano-Sciences, \u201cBabes-Bolyai\u201d University, T. Laurean 42, RO-400271 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ileana","family":"Florea","sequence":"additional","affiliation":[{"name":"LPICM, CNRS, Ecole Polytechnique, IPParis, 91228 Palaiseau, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandrine","family":"Tuseau-Nenez","sequence":"additional","affiliation":[{"name":"Laboratoire de Physique de la Mati\u00e8re Condens\u00e9e, Ecole Polytechnique, IPParis, 91228 Palaiseau, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6820-2491","authenticated-orcid":false,"given":"Monica","family":"Baia","sequence":"additional","affiliation":[{"name":"Department of Biomolecular Physics, Faculty of Physics, \u201cBabes-Bolyai\u201d University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mihaela","family":"Baibarac","sequence":"additional","affiliation":[{"name":"Laboratory Optical Processes in Nanostructure Materials, National Institute of Materials Physics, Atomistilor str. 405 A, 77125 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3196-4868","authenticated-orcid":false,"given":"Lucian","family":"Baia","sequence":"additional","affiliation":[{"name":"Laboratory of Advanced Materials and Applied Technologies, Institute for Research-Development-Innovation in Applied Natural Sciences, \u201cBabes-Bolyai\u201d University, F\u00e2nt\u00e2nele 30, RO-400294 Cluj-Napoca, Romania"},{"name":"Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, \u201cBabes-Bolyai\u201d University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania"},{"name":"Nanostructured Materials and Bio-Nano-Interfaces Center, Institute of Interdisciplinary Research in Bio-Nano-Sciences, \u201cBabes-Bolyai\u201d University, T. Laurean 42, RO-400271 Cluj-Napoca, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Fort, C.I., and Pop, L.C. (2020). Heavy metal and metalloid electrochemical detection by composite nanostructures. Advanced Nanostructures for Environmental Health, Elsevier.","DOI":"10.1016\/B978-0-12-815882-1.00005-7"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1016\/j.bios.2016.03.068","article-title":"Beyond graphene: Electrochemical sensors and biosensors for biomarkers detection","volume":"1","author":"Bollella","year":"2017","journal-title":"Biosens. Bioelectron."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"9638","DOI":"10.1021\/ja802355u","article-title":"A targetable fluorescent probe for imaging hydrogen peroxide in the mitochondria of living cells","volume":"130","author":"Dickinson","year":"2008","journal-title":"J. Am. Chem. Soc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1007\/s12161-008-9041-4","article-title":"Fast Determination of Cd, Fe, Pb, and Zn in Food using AAS","volume":"2","author":"Domene","year":"2009","journal-title":"Food Anal. Methods"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1378","DOI":"10.1016\/j.talanta.2007.01.072","article-title":"A chemiluminescence sensor for the determination of hydrogen peroxide","volume":"72","author":"Ahirovic","year":"2007","journal-title":"Talanta"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.snb.2015.03.039","article-title":"Multi-analyte detection of chemical species using a conducting polymer nanowire-based sensor array platform","volume":"215","author":"Song","year":"2015","journal-title":"Sensors Actuators B Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1016\/j.snb.2018.04.103","article-title":"Insights into the morphological and structural particularities of highly sensitive porous bismuth-carbon nanocomposites based electrochemical sensors","volume":"268","author":"Rusu","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"893","DOI":"10.1016\/j.matchemphys.2012.12.079","article-title":"Iron doped carbon aerogel\u2014New electrode material for electrocatalytic reduction of H2O2","volume":"138","author":"Fort","year":"2013","journal-title":"Mater. Chem. Phys."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"712","DOI":"10.1016\/j.snb.2015.05.124","article-title":"Bismuth doped carbon xerogel nanocomposite incorporated in chitosan matrix for ultrasensitive voltammetric detection of Pb(II) and Cd(II)","volume":"220","author":"Fort","year":"2015","journal-title":"Sens. Actuators B Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3685","DOI":"10.1039\/C5NR08038J","article-title":"Pt 74 Ag 26 nanoparticle-decorated ultrathin MoS2 nanosheets as novel peroxidase mimics for highly selective colorimetric detection of H2O2 and glucose","volume":"8","author":"Cai","year":"2016","journal-title":"Nanoscale"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1016\/j.snb.2015.02.122","article-title":"A review on detection of heavy metal ions in water\u2014An electrochemical approach","volume":"213","author":"Gumpu","year":"2015","journal-title":"Sens. Actuators B Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1016\/j.talanta.2017.08.033","article-title":"A review of the identification and detection of heavy metal ions in the environment by voltammetry","volume":"178","author":"Lu","year":"2018","journal-title":"Talanta"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"765","DOI":"10.1002\/elan.201200592","article-title":"Graphite composite electrodes bulk-modified with (BiO)2CO3 and Bi2O3 plates-like nanostructures for trace metal determination by anodic stripping voltammetry","volume":"25","author":"Marinho","year":"2013","journal-title":"Electroanalysis"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1250","DOI":"10.1039\/C4NR05838K","article-title":"Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction","volume":"7","author":"Sun","year":"2015","journal-title":"Nanoscale"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2311","DOI":"10.1002\/elan.201600219","article-title":"Carbon aerogel as electrode material for improved direct electron transfer in biosensors incorporating cellobiose dehydrogenase","volume":"28","author":"Fort","year":"2016","journal-title":"Electroanalysis"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.matchemphys.2016.01.061","article-title":"Methanol oxidation at carbon paste electrodes modified with (Pt-Ru)\/carbon aerogels nanocomposites","volume":"172","author":"Fort","year":"2016","journal-title":"Mater. Chem. Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"930","DOI":"10.1016\/j.electacta.2017.10.131","article-title":"EDTA_PANI\/ SWCNTs nanocomposite modified electrode for electrochemical determination of copper (II), lead (II) and mercury (II) ions","volume":"259","author":"Deshmukh","year":"2018","journal-title":"Electrochim. Acta"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.bios.2014.01.014","article-title":"Investigations of an electrochemical platform based on the layered MoS2-graphene and horseradish peroxidase nanocomposite for direct electrochemistry and electrocatalysis","volume":"56","author":"Song","year":"2014","journal-title":"Biosens. Bioelectron."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"037531","DOI":"10.1149\/1945-7111\/ab644a","article-title":"Review\u2014Non-Enzymatic Hydrogen Peroxide Electrochemical Sensors Based on Reduced Graphene Oxide","volume":"167","author":"Shamkhalichenar","year":"2020","journal-title":"J. Electrochem. Soc."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.trac.2018.04.012","article-title":"Nanomaterials-based electrochemical detection of heavy metals in water: Current status, challenges and future direction","volume":"105","author":"Waheed","year":"2018","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1405","DOI":"10.1002\/elan.200970017","article-title":"A Decade with Bismuth-Based Electrodes in Electroanalysis","volume":"22","author":"Prior","year":"2010","journal-title":"Electroanalysis"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"11410","DOI":"10.1039\/c3ta12190a","article-title":"Facile synthesis of porous bismuth-carbon nanocomposites for the sensitive detection of heavy metals","volume":"1","author":"Gich","year":"2013","journal-title":"J. Mater. Chem. A"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Fort, C.I., Rusu, M.M., Pop, L.C., Cotet, L.C., Vulpoi, A., Baia, M., and Baia, L. (2020). Preparation and Characterization of Carbon Xerogel Based Composites for Electrochemical Sensing and Photocatalytic Degradation. J. Nanosci. Nanotechnol.","DOI":"10.1166\/jnn.2021.18963"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2772","DOI":"10.1016\/j.jnoncrysol.2006.03.039","article-title":"Synthesis and structural characteristics of carbon aerogels with a high content of Fe, Co, Ni, Cu, and Pd","volume":"352","author":"Cotet","year":"2006","journal-title":"J. Non. Cryst. Solids"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1146\/annurev-matsci-070115-032140","article-title":"Raman Studies of Carbon Nanostructures","volume":"46","author":"Jorio","year":"2016","journal-title":"Annu. Rev. Mater. Res."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/j.carbon.2016.05.065","article-title":"The effect of iron catalyzed graphitization on the textural properties of carbonized cellulose: Magnetically separable graphitic carbon bodies for catalysis and remediation","volume":"107","author":"Hoekstra","year":"2016","journal-title":"Carbon N. Y."},{"key":"ref_27","unstructured":"Rouquerol, F., Rouquerol, J., Sing, K.S.W., Llewellyn, P., Maurin, G.B.T.-A.P., and Second, P.S.E. (2014). Adsorption by Powders and Porous Solids. Adsorption by Powders and Porous Solids, Elsevier."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1280","DOI":"10.1039\/C8TC04908D","article-title":"Formation of bismuth iron oxide based core\u2013shell structures and their dielectric, ferroelectric and magnetic properties","volume":"7","author":"Panda","year":"2019","journal-title":"J. Mater. Chem. C"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1002\/cnma.201600110","article-title":"Nanostructured Iron Oxide\/Hydroxide-Based Electrode Materials for Supercapacitors","volume":"2","author":"Xia","year":"2016","journal-title":"ChemNanoMat"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.talanta.2010.04.018","article-title":"Direct electrocatalytic oxidation of nitric oxide and reduction of hydrogen peroxide based on \u03b1-Fe2O3 nanoparticles-chitosan composite","volume":"82","author":"Zhang","year":"2010","journal-title":"Talanta"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"9037","DOI":"10.1039\/D0NJ00526F","article-title":"Efficiency improvement in non-enzymatic H2O2 detection induced by the simultaneous synthesis of Au and Ag nanoparticles in an RGO\/Au\/Fe3O4\/Ag nanocomposite","volume":"44","author":"Heydaryan","year":"2020","journal-title":"New J. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"63662","DOI":"10.1039\/C5RA10540D","article-title":"Design and preparation of a non-enzymatic hydrogen peroxide sensor based on a novel rigid chain liquid crystalline polymer\/reduced graphene oxide composite","volume":"5","author":"Yang","year":"2015","journal-title":"RSC Adv."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1016\/j.talanta.2018.06.003","article-title":"Sensitive nonenzymatic detection of hydrogen peroxide at nitrogen-doped graphene supported-CoFe nanoparticles","volume":"188","author":"Hassan","year":"2018","journal-title":"Talanta"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1148","DOI":"10.1016\/j.snb.2017.08.002","article-title":"Electrochemical detection of hydrogen peroxide on a new microporous Ni\u2013metal organic framework material-carbon paste electrode","volume":"254","author":"Sherino","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1016\/j.snb.2017.05.124","article-title":"Ultrasensitive electrochemical detection of H2O2 in living cells based on ultrathin MnO2 nanosheets","volume":"252","author":"Shu","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_36","unstructured":"European Drinking Water Directive: 1 (2008). Council Directive 92008\/105\/EC of 16 December 2008 on Environmental Quality Standards in the ELD of Water Policy, European Union. Vol OJ L 348\/84 24.12.2008, 1998 (Chapter Annex 1)."},{"key":"ref_37","first-page":"183","article-title":"Guidelines for Drinking-Water Quality, 2nd edition, Addendum to Volume 1\u2014Recommendations, World Health Organisation, Geneva, 1998, 36 pages","volume":"1","author":"Graham","year":"1999","journal-title":"Urban. Water"}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/1\/117\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:47:34Z","timestamp":1760179654000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/1\/117"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,29]]},"references-count":37,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["molecules26010117"],"URL":"https:\/\/doi.org\/10.3390\/molecules26010117","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,29]]}}}