title: A new nanoprobe based on FRET between functional quantum dots and gold nanoparticles for fluoride anion and its applications for biological imaging.
abstract: A new nanoprobe was designed for the fluorescence imaging of fluoride anion (F(-)) in living cells with high sensitivity and selectivity. The design is based on the fluorescence resonance energy transfer (FRET) between CdTe quantum dots (CdTe QDs) and gold nanoparticles (AuNPs) through the formation of cyclic esters between phenylborinic acid and diol. In the presence of F(-), the boronate ester, a "hard acid", strongly reacts with F(-), a "hard base". Therefore, the boronate ester is converted to trifluoro borate, which causes the breakage of the linkage and disassembles CdTe QDs from AuNPs, resulting in the fluorescence recovery of the quenched CdTe QDs. The interaction mechanism was investigated by (19)FNMR on a model that was constructed by a small molecule and F(-). Quantum chemical calculations also testify the reactivity of boronate ester to F(-) and the sensing mechanism. Experimental results show that the increase in fluorescence intensity is proportional to the concentration of F(-) in the range of 5.0-45 μM. The detection limit and the relative standard deviation were 50 nM and 2.6%, respectively. Fluorescence imaging of F(-) in macrophages cells indicates good cell membrane penetration ability and low cytotoxicity of the nanoprobe, providing a viable alternative to detection of F(-) in biological or environmental samples.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Shandong Normal University, Jinan, PR China.
authors.forename: Mei
authors.initials: M
authors.lastname: Xue
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Duan
authors.forename: Wen
authors.initials: W
authors.lastname: Gao
authors.forename: Lifei
authors.initials: L
authors.lastname: Ji
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D002460:Cell Line; D004952:Esters / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D005459:Fluorides / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D008264:Macrophages / Q000737:chemistry / Q000166:cytology; D053768:Metal Nanoparticles / Q000737:chemistry*; D057054:Molecular Imaging / Q000379:methods*; D011412:Propanolamines / Q000737:chemistry*; D045663:Quantum Dots; D013691:Tellurium / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D004952:Esters; D011412:Propanolamines; C063408:1-aminopropanediol; D006046:Gold; D013691:Tellurium; D005459:Fluorides; C028337:cadmium telluride