Studyontechnetium-99mlabelingofgrapheneoxidenanosheetsthroughclickchemistry–99mTclabelingofgrapheneoxidenanosheets

Graphene oxide(GO)nanosheets possess several advantages,such as a large surface,outstanding biocompatibility,and straightforward chemical modification capability.They also have great potential as a drugcarrier.In this article,we radiolabeled GO nanosheets with99mTc,which satisfies the potential needs of microSPECT imaging probes in pre-clinical and clinical research.GO nanosheets were synthesized through the modified Hummers’method,then GO nanosheets with azide group covalently functionalized in two steps were conjugated to DOTA(1,4,7,10-tetraazacyclododecane-N,N,N,N-tetraacetic acid)and functionalized with an alkynyl group by means of click chemistry.Then through the addition and reduction of technetium-99m,the99mTc-DOTA-GO were attained.DOTA-conjugated GOs with lateral dimensions of 500–600 nm were synthesized.Both atomic force microscopy(AFM)and FT-IR were performed to characterize the GO-DOTA.Labeling efficiency of GO-DOTA with99mTc was>90%and radiochemical purities were>96%with purification.We successfully synthesized graphene oxide derivatives,DOTA-conjugated GOs,via Click Chemistry,and it was labeled with99mTc for SPECT imaging.High radiolabeling efficiency makes GO nanosheets suitable platforms for future molecular imaging research.