{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T20:13:27Z","timestamp":1773260007842,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2018,2,23]],"date-time":"2018-02-23T00:00:00Z","timestamp":1519344000000},"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>Gold nanoclusters (Au NCs) have been considered as novel heavy metal ions sensors due to their ultrafine size, photo-stability and excellent fluorescent properties. In this study, a green and facile method was developed for the preparation of fluorescent water-soluble gold nanoclusters with methionine as a stabilizer. The nanoclusters emit orange fluorescence with excitation\/emission peaks at 420\/565 nm and a quantum yield of about 1.46%. The fluorescence of the Au NCs is selectively and sensitively enhanced by addition of Cd(II) ions attributed to the Cd(II) ion-induced aggregation of nanoclusters. This finding was further used to design a fluorometric method for the determination of Cd(II) ions, which had a linear response in the concentration range from 50 nM to 35 \u03bcM and a detection limit of 12.25 nM. The practicality of the nanoprobe was validated in various environmental water samples and milk powder samples, with a fairly satisfactory recovery percent.<\/jats:p>","DOI":"10.3390\/s18020658","type":"journal-article","created":{"date-parts":[[2018,2,23]],"date-time":"2018-02-23T12:41:40Z","timestamp":1519389700000},"page":"658","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["Methionine-Capped Gold Nanoclusters as a Fluorescence-Enhanced Probe for Cadmium(II) Sensing"],"prefix":"10.3390","volume":"18","author":[{"given":"Yan","family":"Peng","sequence":"first","affiliation":[{"name":"Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China"},{"name":"College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, Xinjiang, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maomao","family":"Wang","sequence":"additional","affiliation":[{"name":"Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoxia","family":"Wu","sequence":"additional","affiliation":[{"name":"Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fu","family":"Wang","sequence":"additional","affiliation":[{"name":"Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lang","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, Xinjiang, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,2,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1002\/chem.201404224","article-title":"A highly selective two-photon fluorescent probe for detection of cadmium(II) based on intramolecular electron transfer and its imaging in living cells","volume":"21","author":"Shi","year":"2015","journal-title":"Chemistry"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2797","DOI":"10.1039\/C4NR06467D","article-title":"Bipyridine hydrogel for selective and visible detection and absorption of Cd2+","volume":"7","author":"Miao","year":"2015","journal-title":"Nanoscale"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"455","DOI":"10.1007\/s00604-007-0775-2","article-title":"Flow injection on-line hydrophobic sorbent extraction for flame atomic absorption spectrometric determination of cadmium in water samples","volume":"160","author":"Anthemidis","year":"2008","journal-title":"Microchim. Acta"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1039\/C5JA00300H","article-title":"Significant signal enhancement of dielectric barrier discharge plasma induced vapor generation by using non-ionic surfactants for determination of mercury and cadmium by atomic fluorescence spectrometry","volume":"31","author":"Li","year":"2015","journal-title":"J. Anal. At. Spectrom."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1144","DOI":"10.1016\/j.talanta.2006.06.005","article-title":"Direct determination of cadmium in urine by tungsten-coil inductively coupled plasma atomic emission spectrometry using palladium as a permanent modifier","volume":"71","author":"Davis","year":"2007","journal-title":"Talanta"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.cplett.2016.10.081","article-title":"A simple polyethylenimine-salicylaldehyde fluorescence probe: Sensitive and selective detection of Zn2+ and Cd2+ in aqueous solution by adding S2\u2212 ion","volume":"666","author":"Tan","year":"2016","journal-title":"Chem. Phys. Lett."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"877","DOI":"10.1016\/j.snb.2017.05.103","article-title":"A novel 2-(hydroxymethyl)quinolin-8-ol-based selective and sensitive fluorescence probe for Cd2+ ion in water and living cells","volume":"251","author":"Dai","year":"2017","journal-title":"Sens. Actuators B"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6138","DOI":"10.1039\/c0cc00662a","article-title":"A highly sensitive ratiometric fluorescent probe for Cd2+ detection in aqueous solution and living cells","volume":"46","author":"Liu","year":"2010","journal-title":"Chem. Commun."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"9593","DOI":"10.1039\/C6NJ01682K","article-title":"A novel fluorene based \u201cturn on\u201d fluorescent sensor for the determination of zinc and cadmium: Experimental and theoretical studies along with live cell imaging","volume":"40","author":"Roy","year":"2016","journal-title":"New J. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2211","DOI":"10.1039\/C7OB00201G","article-title":"A 4,5-quinolimide-based fluorescent sensor for the turn-on detection of Cd2+ with live-cell imaging","volume":"15","author":"Zhang","year":"2017","journal-title":"Org. Biomol. Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"10041","DOI":"10.1021\/ic2008182","article-title":"A highly selective on\/off fluorescence sensor for cadmium(II)","volume":"50","author":"Zhao","year":"2011","journal-title":"Inorg. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"12087","DOI":"10.1039\/C6DT01398H","article-title":"A selective fluorescent probe for the detection of Cd2+ in different buffer solutions and water","volume":"45","author":"Xu","year":"2016","journal-title":"Dalton Trans."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1016\/j.dyepig.2017.05.001","article-title":"A porphyrin-based fluorescent probe for optical detection of toxic Cd2+ ion in aqueous solution and living cells","volume":"143","author":"Huang","year":"2017","journal-title":"Dyes Pigments"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1346","DOI":"10.1016\/j.snb.2015.07.049","article-title":"Thioglycerol-functionalized CdSe quantum dots detecting cadmium ions","volume":"220","author":"Brahim","year":"2015","journal-title":"Sens. Actuators B"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3037","DOI":"10.1039\/b803166e","article-title":"A simple strategy for quantum dot assisted selective detection of cadmium ions","volume":"26","author":"Banerjee","year":"2008","journal-title":"Chem. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1361","DOI":"10.1007\/s00604-014-1264-z","article-title":"Quantum dot-based turn-on fluorescent probe for imaging intracellular zinc(II) and cadmium(II) ions","volume":"181","author":"Luo","year":"2014","journal-title":"Microchim. Acta"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"6616","DOI":"10.1021\/acs.analchem.7b00777","article-title":"Synthesis of water-soluble Ag2S quantum dots with fluorescence in the second near-infrared window for turn-on detection of Zn(II) and Cd(II)","volume":"89","author":"Wu","year":"2017","journal-title":"Anal. Chem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"9839","DOI":"10.1021\/ac4023764","article-title":"Silver-gold alloy nanoclusters as a fluorescence-enhanced probe for aluminum ion sensing","volume":"85","author":"Zhou","year":"2013","journal-title":"Anal. Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/j.nantod.2011.06.004","article-title":"Ultra-small fluorescent metal nanoclusters: Synthesis and biological applications","volume":"6","author":"Shang","year":"2011","journal-title":"Nano Today"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1078","DOI":"10.1002\/adma.200904199","article-title":"Water-soluble fluorescent silver nanoclusters","volume":"22","author":"Xu","year":"2010","journal-title":"Adv. Mater."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3594","DOI":"10.1039\/c2cs15325d","article-title":"Sub-nanometre sized metal clusters: From synthetic challenges to the unique property discoveries","volume":"41","author":"Lu","year":"2012","journal-title":"Chem. Soc. Rev."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"858","DOI":"10.1002\/asia.201201236","article-title":"Luminescent noble metal nanoclusters as an emerging optical probe for sensor development","volume":"8","author":"Yuan","year":"2013","journal-title":"Chem. Asian J."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2185","DOI":"10.1021\/am405345h","article-title":"Purine-stabilized green fluorescent gold nanoclusters for cell nuclei imaging applications","volume":"6","author":"Venkatesh","year":"2014","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"19731","DOI":"10.3390\/s141019731","article-title":"Recent advances in the field of bionanotechnology: An insight into optoelectric bacteriorhodopsin, quantum dots, and noble metal nanoclusters","volume":"14","author":"Knoblauch","year":"2014","journal-title":"Sensors"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1034","DOI":"10.1016\/j.carbon.2015.10.051","article-title":"Dumbbell-shaped carbon quantum dots\/auncs nanohybrid as an efficient ratiometric fluorescent probe for sensing cadmium(II) ions and l-ascorbic acid","volume":"96","author":"Niu","year":"2016","journal-title":"Carbon"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"840","DOI":"10.1016\/j.snb.2016.10.116","article-title":"Sunlight and ultrasound-assisted synthesis of photoluminescent silver nanoclusters: A unique \u2018knock out\u2019 sensor for thiophilic metal ions","volume":"241","author":"Naaz","year":"2017","journal-title":"Sens. Actuators B"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"5170","DOI":"10.1021\/ac3006268","article-title":"Binding-induced fluorescence turn-on assay using aptamer-functionalized silver nanocluster DNA probes","volume":"84","author":"Li","year":"2012","journal-title":"Anal. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1007\/s11051-016-3630-8","article-title":"Colorimetric detection of Cd2+ using 1-amino-2-naphthol-4-sulfonic acid functionalized silver nanoparticles","volume":"18","author":"Huang","year":"2016","journal-title":"J. Nanopart. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/j.jcis.2014.12.046","article-title":"Synthesis of gold nanoparticles using various amino acids","volume":"447","author":"Maruyama","year":"2015","journal-title":"J. Colloid Interface Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4073","DOI":"10.1039\/c2nr31192e","article-title":"Different sized luminescent gold nanoparticles","volume":"4","author":"Zheng","year":"2012","journal-title":"Nanoscale"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2009","DOI":"10.1039\/c0nr00947d","article-title":"Facile preparation of water-soluble fluorescent gold nanoclusters for cellular imaging applications","volume":"3","author":"Shang","year":"2011","journal-title":"Nanoscale"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.aca.2014.05.050","article-title":"Novel synthesis of gold nanoclusters templated with l-tyrosine for selective analyzing tyrosinase","volume":"840","author":"Yang","year":"2014","journal-title":"Anal. Chim. Acta"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"6445","DOI":"10.1039\/C4AY01137F","article-title":"One-pot synthesis of tyrosine-stabilized fluorescent gold nanoclusters and their application as turn-on sensors for Al3+ ions and turn-off sensors for Fe3+ ions","volume":"6","author":"Mu","year":"2014","journal-title":"Anal. Methods"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"7056","DOI":"10.1002\/anie.201100299","article-title":"Insulin-directed synthesis of fluorescent gold nanoclusters: Preservation of insulin bioactivity and versatility in cell imaging","volume":"50","author":"Liu","year":"2011","journal-title":"Angew. Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2614","DOI":"10.1002\/smll.201100746","article-title":"One-pot synthesis of near-infrared fluorescent gold clusters for cellular fluorescence lifetime imaging","volume":"7","author":"Shang","year":"2011","journal-title":"Small"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1126\/science.1150176","article-title":"Nano-golden order","volume":"318","author":"Whetten","year":"2007","journal-title":"Science"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"4951","DOI":"10.1007\/s00216-017-0436-1","article-title":"A multifunctional fluorescent aptamer probe for highly sensitive and selective detection of cadmium(II)","volume":"409","author":"Zhu","year":"2017","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3433","DOI":"10.1021\/cr100383r","article-title":"Recent trends in macro-, micro-, and nanomaterial-based tools and strategies for heavy-metal detection","volume":"111","author":"Aragay","year":"2011","journal-title":"Chem. Rev."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/2\/658\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:56:07Z","timestamp":1760194567000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/2\/658"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,2,23]]},"references-count":38,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2018,2]]}},"alternative-id":["s18020658"],"URL":"https:\/\/doi.org\/10.3390\/s18020658","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,2,23]]}}}