A general thiol assay based on the suppression of fluorescence resonance energy transfer in magnetic-resin core-shell nanospheres coated with gold nanoparticles

作者：Roman Pizarro Vanessa; Gulzar Umair; Manuel Fernandez Romero Juan; Gomez Hens Agustina^*

来源：Microchimica Acta, 2015, 182(13-14): 2285-2292.

DOI：10.1007/s00604-015-1579-4

• Fluorescence surfactant enhancement
• Magnetic-phenol/formaldehyde resin
• Gold nanospheres
• Fluorescence resonance energy transfer
• Thiols
• Water samples

A simple, rapid and sensitive fluorescence resonance energy transfer (FRET) method is presented for the determination of thiols. It is based on the thiol-induced enhancement effect of the surfactant sodium dodecyl sulfate (SDS) on the efficiency of fluorescence resonance energy transfer (FRET) in nanospheres consisting of a magnetic (Fe3O4) core and a phenol-formaldehyde resin (PFR) shell containing gold nanoparticles (AuNPs). The luminescence of the core-shell nanospheres at excitation/emission wavelengths of 390/445 nm, respectively, is quenched by the AuNPs which act as energy acceptors. The interaction of AuNPs with thiol compounds in the presence of SDS suppresses FRET and gives rise to a fluorescent signal whose intensity is proportional to the thiol concentration. The analytical features of seven thiols (homocysteine, thioglycolic acid, glutathione, dodecanethiol, cysteamine, cysteine and N-acetylcysteine) were studied. Detection limits are in the range from 0.14 to 0.49 mu mol L-1. The precision of the method, expressed as the relative standard deviation, ranges from 0.4 to 4.9 %. The method was applied to the determination of total thiols in water samples with recovery values between 88.7 and 104.6 %.

• 出版日期2015-10