{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,19]],"date-time":"2026-01-19T08:36:23Z","timestamp":1768811783182,"version":"3.49.0"},"reference-count":51,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,12,21]],"date-time":"2021-12-21T00:00:00Z","timestamp":1640044800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Sodium diclofenac (DCF) presence reported in water use cycle at various concentrations including trace levels necessitates continuous development of advanced analytical method for its determination. In this work, ease electrochemical methods for DCF determination based on voltammetric and amperometric techniques were proposed using a simple combination of graphene with multi-walled carbon nanotubes as paste electrode. Integration of the graphene with multi-walled carbon nanotubes enlarged the electroactive surface area of the electrode and implicitly enhanced the electrochemical response for DCF determination. On the basis of the sorption autocatalytic effect manifested at low concentration of DCF, we found that the preconcentration step applied prior to differential-pulsed voltammetry (DPV) and multiple-pulsed amperometry (MPA) allowed for the enhancement of the electroanalytical performance of the DCF electrochemical detections, which were validated by testing in tap water. The lowest limit of detection (LOD) of 1.40 ng\u00b7L\u22121 was found using preconcentration prior to DPV under optimized operating conditions, which is better than that reached by other carbon-based electrodes reported in the literature.<\/jats:p>","DOI":"10.3390\/ijerph19010029","type":"journal-article","created":{"date-parts":[[2021,12,21]],"date-time":"2021-12-21T09:50:43Z","timestamp":1640080243000},"page":"29","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Electrochemical Method for Ease Determination of Sodium Diclofenac Trace Levels in Water Using Graphene\u2014Multi-Walled Carbon Nanotubes Paste Electrode"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0488-8452","authenticated-orcid":false,"given":"Sorina","family":"Motoc","sequence":"first","affiliation":[{"name":"\u201cCoriolan Dr\u0103gulescu\u201d Institute of Chemistry, Romanian Academy, 24 Mihai Viteazu Bvd., 300223 Timisoara, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1285-6634","authenticated-orcid":false,"given":"Florica","family":"Manea","sequence":"additional","affiliation":[{"name":"Department of Applied Chemistry and Engineering of Inorganic Compounds and Environment, Politehnica University of Timisoara, 6 Bv. V. Parvan, 300223 Timisoara, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anamaria","family":"Baciu","sequence":"additional","affiliation":[{"name":"Department of Applied Chemistry and Engineering of Inorganic Compounds and Environment, Politehnica University of Timisoara, 6 Bv. V. Parvan, 300223 Timisoara, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Corina","family":"Orha","sequence":"additional","affiliation":[{"name":"National Condensed Matter Department, Institute for Research and Development in Electrochemistry and Condensed Matter Timisoara, 1 P. Andronescu Street, 300254 Timisoara, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aniela","family":"Pop","sequence":"additional","affiliation":[{"name":"Department of Applied Chemistry and Engineering of Inorganic Compounds and Environment, Politehnica University of Timisoara, 6 Bv. V. Parvan, 300223 Timisoara, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1242","DOI":"10.1080\/03067319.2015.1085520","article-title":"Occurrence of pharmaceuticals in surface waters: Analytical method development and environmental risk assessment","volume":"95","author":"Nannou","year":"2015","journal-title":"Int. J. Environ. Anal. Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.jhazmat.2014.06.069","article-title":"Environmental side effects of pharmaceutical cocktails: What we know and what we should know","volume":"279","author":"Vasquez","year":"2014","journal-title":"J. Hazard. Mater."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"730","DOI":"10.1016\/j.jhazmat.2008.05.089","article-title":"Pharmaceutical compound content of municipal solid waste","volume":"162","author":"Musson","year":"2009","journal-title":"J. Hazard. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"823","DOI":"10.1002\/etc.3339","article-title":"Pharmaceuticals in the environment-global occurrences and perspectives: Pharmaceuticals in the global environment","volume":"35","author":"Weber","year":"2016","journal-title":"Environ. Toxicol. Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1080\/15275922.2019.1597780","article-title":"Naproxen, ibuprofen, and diclofenac residues in river water, sediments and Eichhornia crassipes of Mbokodweni river in South Africa: An initial screening","volume":"20","author":"Naicker","year":"2019","journal-title":"Environ. Forensics"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.arabjc.2010.12.006","article-title":"Spectrophotometric and spectrofluorometric methods for the determination of non-steroidal anti-inflammatory drugs: A review","volume":"6","author":"Gouda","year":"2013","journal-title":"Arab. J. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.jpba.2016.05.037","article-title":"Determination of ibuprofen, naproxen and diclofenac in aqueous samples using a multi-template molecularly imprinted polymer as selective adsorbent for solid-phase extraction","volume":"128","author":"Madikizela","year":"2016","journal-title":"J. Pharm. Biomed."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.watres.2014.08.053","article-title":"A review on emerging contaminants in wastewaters and the environment: Current knowledge, understudied areas and recommendations for future monitoring","volume":"72","author":"Petrie","year":"2015","journal-title":"Water Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"575","DOI":"10.1039\/D0AY02098B","article-title":"A review of pharmaceutical occurrence and pathways in the aquatic environment in the context of a changing climate and the COVID-19 pandemic","volume":"13","author":"Lawler","year":"2021","journal-title":"Anal. Methods"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"264","DOI":"10.4314\/wsa.v43i2.10","article-title":"Simultaneous determination of naproxen, ibuprofen and diclofenac in wastewater using solid-phase extraction with high performance liquid chromatography","volume":"43","author":"Madikizela","year":"2017","journal-title":"Water SA"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1080\/03067310903243936","article-title":"Determination of selected non-steroidal anti-inflammatory drugs in wastewater by gas chromatography-mass spectrometry","volume":"90","author":"Samaras","year":"2010","journal-title":"Int. J. Environ. Anal. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1093\/jat\/25.4.237","article-title":"Screening procedure for detection of non-steroidal anti-inflammatory drugs and their metabolites in urine as part of a systematic toxicological analysis procedure for acidic drugs and poisons by gas chromatography- mass spectrometry after extractive methylation","volume":"25","author":"Maurer","year":"2001","journal-title":"J. Anal. Toxicol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1016\/j.talanta.2019.03.062","article-title":"Simultaneous determination of non-steroidal anti-inflammatory drugs and natural estrogens in the mussels Mytilus edulis trossulus","volume":"200","author":"Wolecki","year":"2019","journal-title":"Talanta"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"242868","DOI":"10.1155\/2013\/242868","article-title":"RP-HPLC method for determination of several NSAIDs and their combination drugs","volume":"2013","author":"Patel","year":"2013","journal-title":"Chromatogr. Res. Int."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2901","DOI":"10.1002\/bkcs.10601","article-title":"Simultaneous determination of nonsteroidal anti-inflammatory drugs in aqueous samples using dispersive liquid-liquid microextraction and HPLC analysis","volume":"36","author":"Park","year":"2015","journal-title":"Bull. Korean Chem. Soc. B"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3701","DOI":"10.1002\/elps.200800153","article-title":"Determination of pharmaceuticals classified as emerging pollutants using capillary electrophoresis with capacitively coupled contactless conductivity detection","volume":"29","author":"Quek","year":"2008","journal-title":"Electrophoresis"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1000226","DOI":"10.4172\/2167-7662.1000226","article-title":"Nanomaterials for pharmaceuticals determination","volume":"5","author":"Saleh","year":"2016","journal-title":"Bioenergetics"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1016\/j.jpba.2017.06.062","article-title":"Electrochemical carbon based nanosensors: A promising tool in pharmaceutical and biomedical analysis","volume":"147","author":"Kurbanoglu","year":"2018","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Hu, J., and Zhang, Z. (2020). Application of electrochemical sensors based on carbon nanomaterials for detection of flavonoids. Nanomaterials, 10.","DOI":"10.3390\/nano10102020"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Torrinha, A., Oliveira, T.M.B.F., Ribeiro, F.W.P., Correia, A.N., Lima-Neto, P., and Morais, S. (2020). Application of nanostructured carbon-based electrochemical (Bio)sensors for screening of emerging pharmaceutical pollutants in waters and aquatic species: A review. Nanomaterials, 10.","DOI":"10.3390\/nano10071268"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"935","DOI":"10.1007\/s00604-013-1015-6","article-title":"Carbon nanomaterial based electrochemical sensors for biogenic amines","volume":"180","author":"Yang","year":"2013","journal-title":"Microchim. Acta"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1515\/ntrev-2017-0160","article-title":"Carbon nanomaterials and their application to electrochemical sensors: A review","volume":"7","author":"Power","year":"2018","journal-title":"Nanotechnol. Rev."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"115624","DOI":"10.1016\/j.trac.2019.115624","article-title":"Carbon based nanomaterials\u2014A promising electrochemical sensor toward persistent toxic substance","volume":"119","author":"Xie","year":"2019","journal-title":"Trends Analyt. Chem."},{"key":"ref_24","unstructured":"Siqueira, J.R., and de Oliveira, O.N. (2017). Nanostructures, Elsevier."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1021\/acsnano.5b05690","article-title":"Engineered carbon-nanomaterial-based electrochemical sensors for biomolecules","volume":"10","author":"Tiwari","year":"2015","journal-title":"ACS Nano"},{"key":"ref_26","unstructured":"Manea, F. (2017). Modern Electrochemical Methods in Nano, Surface and Corrosion Science, IntechOpen."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Pan, M., Yin, Z., Liu, K., Du, X., Liu, H., and Wang, S. (2019). Carbon-based nanomaterials in sensors for food safety. Nanomaterials, 9.","DOI":"10.3390\/nano9091330"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Motoc, S., Manea, F., Orha, C., and Pop, A. (2019). Enhanced electrochemical response of diclofenac at a fullerene-carbon nanofiber paste electrode. Sensors, 19.","DOI":"10.3390\/s19061332"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1682","DOI":"10.1016\/j.msec.2012.04.066","article-title":"MWCNTs\/Cu(OH)2 nanoparticles\/IL nanocomposite modified glassy carbon electrode as a voltammetric sensor for determination of the non-steroidal anti-inflammatory drug diclofenac","volume":"32","author":"Arvand","year":"2012","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"19951","DOI":"10.1016\/j.ijhydene.2017.06.163","article-title":"Immobilized copper ions on MWCNTS-Chitosan thin film: Enhanced amperometric sensor for electrochemical determination of diclofenac sodium in aqueous solution","volume":"42","author":"Shalauddin","year":"2017","journal-title":"Int. J. Hydrogen Energy"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1007\/s11581-012-0705-0","article-title":"Sensitive voltammetric determination of diclofenac using room-temperature ionic liquid-modified carbon nanotubes paste electrode","volume":"19","author":"Ensafi","year":"2012","journal-title":"Ionics"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/j.microc.2018.09.009","article-title":"Fabrication of a new electrochemical sensor based on Au Pt bimetallic nanoparticles decorated multi-walled carbon nanotubes for determination of diclofenac","volume":"144","author":"Eteya","year":"2018","journal-title":"Microchem. J."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Motoc, S., Manea, F., Iacob, A., Martinez-Joaristi, A., Gascon, J., Pop, A., and Schoonman, J. (2016). Electrochemical selective and simultaneous detection of diclofenac and ibuprofen in aqueous solution using HKUST-1 metal-organic framework-carbon nanofiber composite elect. Sensors, 16.","DOI":"10.3390\/s16101719"},{"key":"ref_34","first-page":"2096","article-title":"Electrochemical determination of diclofenac using boron-doped diamond electrode","volume":"13","author":"Ihos","year":"2012","journal-title":"J. Environ. Prot. Ecol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2058","DOI":"10.1002\/elan.201000074","article-title":"Electrochemical determination of diclofenac sodium in aqueous Solution on cu-doped zeolite-expanded graphite-epoxy electrode","volume":"22","author":"Manea","year":"2010","journal-title":"Electroanalysis"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"100026","DOI":"10.1016\/j.talo.2020.100026","article-title":"Electrochemical sensors and biosensors for the determination of diclofenac in pharmaceutical, biological and water samples","volume":"3","author":"Boumya","year":"2021","journal-title":"Talanta Open"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"740","DOI":"10.3390\/nano11030740","article-title":"CuBi2O4 synthesis, characterization, and application in sensitive amperometric\/voltammetric detection of amoxicillin in aqueous solutions","volume":"11","author":"Voda","year":"2021","journal-title":"Nanomaterials"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Motoc, S., Cretu, C., Costisor, O., Baciu, A., Manea, F., and Szerb, E.I. (2019). Cu(I) coordination complex precursor for randomized CuOx microarray loaded on carbon nanofiber with excellent electrocatalytic performance for electrochemical glucose detection. Sensors, 19.","DOI":"10.3390\/s19245353"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Motoc, S., Schinteie, B., Pop, A., Negrea, S., Cretu, C., Szerb, E.I., and Manea, F. (2021). Graphene quantum dots and Cu(I) liquid crystal for advanced electrochemical detection of doxorubicine in aqueous solutions. Nanomaterials, 11.","DOI":"10.3390\/nano11112788"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1741","DOI":"10.1021\/ac50160a042","article-title":"Diffusion coefficients of ferri- and ferrocyanide ions in aqueous media, using twin-electrode thin-layer electrochemistry","volume":"42","author":"Konopka","year":"1970","journal-title":"Anal. Chem."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Negrea, S., Diaconu, L.A., Nicorescu, V., Motoc, S., Orha, C., and Manea, F. (2021). Graphene oxide electroreduced onto boron-doped diamond and electrodecorated with silver (Ag\/GO\/BDD) electrode for tetracycline detection in aqueous solution. Nanomaterials, 11.","DOI":"10.3390\/nano11061566"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"685081","DOI":"10.1155\/2011\/685081","article-title":"Synthesis, properties, and applications of low-dimensional carbon-related nanomaterials","volume":"2011","author":"Mostofizadeh","year":"2011","journal-title":"J. Nanomater."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1021\/nl025952c","article-title":"Photoluminescence and electronic interaction of anthracene derivatives adsorbed on sidewalls of single-walled carbon nanotubes","volume":"3","author":"Zhang","year":"2003","journal-title":"Nano Lett."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"100002","DOI":"10.1016\/j.sintl.2020.100002","article-title":"Electrochemical behavior of diclofenac sodium at coreshell nanostructure modified electrode and its analysis in human urine and pharmaceutical samples","volume":"1","author":"Honakeri","year":"2020","journal-title":"Sens. Int."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.electacta.2016.03.094","article-title":"New insigths on the kinetics and me-chanism of the electrochemical oxidation of diclofenac in neutral aqueous medium","volume":"199","author":"Galano","year":"2016","journal-title":"Electrochim. Acta"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"981","DOI":"10.1002\/elan.200603487","article-title":"Numerical modeling of ECE-ECE and parallel EE-EE mechanisms in cyclic voltammetry. reduction of 1,4-benzenedisulfonyl difluoride and 1,4-naphthalenedisulfonyl difluoride","volume":"18","author":"Sanecki","year":"2006","journal-title":"Electroanalysis"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1016\/j.snb.2010.01.038","article-title":"Electrochemical investigations of diclofenac at edge plane pyrolytic graphite electrode and its determination in human urine","volume":"145","author":"Goyal","year":"2010","journal-title":"Sens. Actuators B Chem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"182","DOI":"10.1016\/j.jelechem.2017.03.050","article-title":"New insights on diclofenac electrochemistry using graphite as working electrode","volume":"794","year":"2017","journal-title":"J. Electroanal. Chem."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Sasal, A., Tyszczuk-Rotko, K., Wojciak, M., and Sowa, I. (2020). First electrochemical sensor (screen-printed carbon electrode modified with carboxyl functionalized multiwalled carbon nanotubes) for ultratrace determination of diclofenac. Materials, 13.","DOI":"10.3390\/ma13030781"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.snb.2012.03.059","article-title":"Application of modified multiwall carbon nanotubes paste electrode for simultaneous voltammetric determination of morphine and diclofenac in biological and pharmaceutical samples","volume":"169","author":"Mokhtari","year":"2012","journal-title":"Sens. Actuators B Chem."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1002\/elan.201500360","article-title":"Simultaneous electrochemical determination of paracetamol and diclofenac based on poly(diallyldimethylammonium chloride) functionalized graphene","volume":"28","author":"Okoth","year":"2015","journal-title":"Electroanalysis"}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/19\/1\/29\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:50:22Z","timestamp":1760169022000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/19\/1\/29"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,21]]},"references-count":51,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2022,1]]}},"alternative-id":["ijerph19010029"],"URL":"https:\/\/doi.org\/10.3390\/ijerph19010029","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,21]]}}}