BiosensorsandBioelectronics32(2012)266–272ContentslistsavailableatSciVerseScienceDirectBiosensorsandBioelectronicsjournalhomepage:www.elsevier.com/locate/biosHighlysensitiveelectrochemicaldetectionofpotentialcytotoxicityofCdSe/ZnSquantumdotsusingneuralcellchipaba,b,∗Tae-HyungKim,WaleedAhmedEl-Said,Jeong-WooChoiaDepartmentofChemical&BiomolecularEngineering,SogangUniversity,35Baekbeom-Ro,Mapo-Gu,Seoul121-742,RepublicofKoreabInterdisciplinaryProgramofIntegratedBiotechnology,SogangUniversity,35Baekbeom-Ro,Mapo-Gu,Seoul121-742,RepublicofKoreaarticleinfoabstractArticlehistory:Cellchipwasrecentlydevelopedasasimpleandhighlysensitivetoolforthetoxicityassessmentofvar-Received14October2011iouskindsofchemicalsornano-materials.Here,wereportnewlydiscoveredpotentialcytotoxiceffectsReceivedinrevisedformofCdSe/ZnSquantumdots(QDs)onintracellularredoxenvironmentofneuralcancercellsatverylow14December2011concentrationswhichcanbeonlydetectedbycellchiptechnology.Green(2.1nmindiameter)andredAccepted20December2011(6.3nmindiameter)QDscappedwithcysteamine(CA)orthioglycolicacid(TA)werefoundtobetoxicatAvailableonline27December2011100␮g/mLwhenassessedbytrypanblueanddifferentialpulsevoltammetry(DPV).However,incaseofconcentration-dependentcytotoxicity,toxiceffectsofTA-cappedQDsonhumanneuralcellswereonlyKeywords:measuredbyDPVmethodwhenconventionalMTTassaydidnotshowtoxicityofTA-cappedQDsatlowCdSe/ZnSquantumdots␮Cytotoxicityconcentrations(1–10g/mL).Red-TAQDsandGreen-TAQDswerefoundtodecreaseelectrochemical␮␮␮Cyclicvoltammetrysignalsfromcellsat10g/mLand5g/mL,respectively,whilecellviabilitydecreasedat100g/mL␮Differentialpulsevoltammetryand50g/mLwhenassessedbyMTTassay,respectively.Therelativedecreasesofcellviabilitydeter-MTTassayminedbyMTTassaywere15%and11.9%whencellsweretreatedwith5–50␮g/mLofRed-TAQDsandNeuralcellchip