Thirumalraj, B.B.ThirumalrajDhenadhayalan, N.N.DhenadhayalanChen, S.-M.S.-M.ChenLiu, Y.-J.Y.-J.LiuChen, T.-W.T.-W.ChenLiang, P.-H.P.-H.LiangLin, K.-C.K.-C.Lin2019-08-012019-08-012018https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038079837&doi=10.1016%2fj.snb.2017.12.028&partnerID=40&md5=d7e120cfefab80b95b1c4b6aae599be1https://scholars.lib.ntu.edu.tw/handle/123456789/416024A highly sensitive and selective fluorogenic sensing of L-Cysteine (L-Cys) was implemented based on gelatin stabilized gold nanoparticles decorated reduced graphene oxide (rGO/Au) nanohybrid. The rGO/Au nanohybrid was prepared by the one-pot hydrothermal method and well characterized by different physiochemical techniques. The nanohybrid exhibits a weak fluorescence of rGO due to the energy transfer from the rGO to Au NPs. The rGO/Au nanohybrid shows enhanced fluorescence activity due to the restoration of quenched fluorescence of rGO/Au nanohybrid in presence of L-Cys. The rGO/Au nanohybrid exhibits much lower detection limit of 0.51 nM for L-Cys with higher selectivity. The fluorescence sensing mechanism arose from the fluorescence recovery due to the stronger interaction between Au NPs and L-Cys, and consequently, the energy transfer was prevented between rGO and Au NPs. The practicability of rGO/Au sensor was implemented by invitro bioimaging measurements in Colo-205 (colorectal adenocarcinoma) and MKN-45 (gastric carcinoma) cancer live cells with excellent biocompatibility. ? 2017 Elsevier B.V.Bioimaging; Energy transfer; Fluorescence; Gold nanoparticles; L-Cysteine; Reduced graphene oxide[SDGs]SDG3Amino acids; Biocompatibility; Energy transfer; Fiber optic sensors; Fluorescence; Gold; Graphene; Metal nanoparticles; Nanoparticles; Bio-imaging; Colorectal adenocarcinoma; Enhanced fluorescence; Gold Nanoparticles; L-cysteine; Lower detection limit; Physiochemical techniques; Reduced graphene oxides; Nanostructured materialsjournal article10.1016/j.snb.2017.12.0282-s2.0-85038079837