{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,17]],"date-time":"2026-04-17T16:05:13Z","timestamp":1776441913375,"version":"3.51.2"},"reference-count":52,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,1,28]],"date-time":"2021-01-28T00:00:00Z","timestamp":1611792000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000015","name":"U.S. Department of Energy","doi-asserted-by":"publisher","award":["FE0030456"],"award-info":[{"award-number":["FE0030456"]}],"id":[{"id":"10.13039\/100000015","id-type":"DOI","asserted-by":"publisher"}]},{"name":"DST\/Intel\u00ae\/Indo-U.S. Science and Technology Forum","award":["IUSSTF\/WAQM-Water-Quality"],"award-info":[{"award-number":["IUSSTF\/WAQM-Water-Quality"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Linker-free magnetite nanoparticles (Fe3O4NPs)-decorated gold nanoparticles (AuNPs) were grown using a new protocol that can be used as a new platform for synthesis of other intact metal\u2013metal oxide nanocomposites without the need for linkers. This minimizes the distance between the metal and metal oxide nanoparticles and ensures the optimum combined effects between the two material interfaces. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy confirmed the successful synthesis of the Fe3O4-Au nanocomposite, without any change in the magnetite phase. Characterization, using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy, revealed the composite to consist of AuNPs of 70 \u00b1 10 nm diameter decorated with tiny 10 \u00b1 3 nm diameter Fe3O4NPs in Au:Fe mass ratio of 5:1. The prepared Fe3O4-Au nanocomposite was embedded in ionic liquid (IL) and applied for the modification of glassy carbon electrode (GCE) for the electrochemical detection of As(III) in water. By combining the excellent catalytic properties of the AuNPs with the high adsorption capacity of the tiny Fe3O4NPs towards As(III), as well as the good conductivity of IL, the Fe3O4-Au-IL nanocomposite showed excellent performance in the square wave anodic stripping voltammetry detection of As(III). Under the optimized conditions, a linear range of 1 to 100 \u03bcg\/L was achieved with a detection limit of 0.22 \u03bcg\/L (S\/N = 3), and no interference from 100-fold higher concentrations of a wide variety of cations and anions found in water. A very low residual standard deviation of 1.16% confirmed the high precision\/reproducibility of As(III) analysis and the reliability of the Fe3O4-Au-IL sensing interface. Finally, this proposed sensing interface was successfully applied to analyzing synthetic river and wastewater samples with a 95\u2013101% recovery, demonstrating excellent accuracy, even in complex synthetic river and wastewater samples containing high concentrations of humic acid without any sample pretreatments.<\/jats:p>","DOI":"10.3390\/s21030883","type":"journal-article","created":{"date-parts":[[2021,1,28]],"date-time":"2021-01-28T09:03:45Z","timestamp":1611824625000},"page":"883","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":36,"title":["Linker-Free Magnetite-Decorated Gold Nanoparticles (Fe3O4-Au): Synthesis, Characterization, and Application for Electrochemical Detection of Arsenic (III)"],"prefix":"10.3390","volume":"21","author":[{"given":"Mohammed","family":"Sedki","sequence":"first","affiliation":[{"name":"Materials Science and Engineering Program, University of California, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guo","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shengcun","family":"Ma","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David","family":"Jassby","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2831-4154","authenticated-orcid":false,"given":"Ashok","family":"Mulchandani","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA"},{"name":"Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, CA 92507, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"866","DOI":"10.1126\/science.1237484","article-title":"Groundwater arsenic contamination throughout China","volume":"341","author":"Sun","year":"2013","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"S93","DOI":"10.1097\/00001648-200007000-00177","article-title":"Arsenic in drinking water and cancer risks estimated from epidemiological studies in Argentina, Chile, Taiwan and Japan","volume":"11","author":"Smith","year":"2000","journal-title":"Epidemiology"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1016\/j.taap.2007.02.012","article-title":"Residential exposure to drinking water arsenic in Inner Mongolia, China","volume":"222","author":"Ning","year":"2007","journal-title":"Toxicol. 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