A new sensitive fluorometric assay method for acetylcholinesterase （ACHE） and its inhibitor was developed us- ing a fluorescent dye, nile red （NR）. Due to the fluorescence resonance energy transfer between the NR ...A new sensitive fluorometric assay method for acetylcholinesterase （ACHE） and its inhibitor was developed us- ing a fluorescent dye, nile red （NR）. Due to the fluorescence resonance energy transfer between the NR and the gold nanoparticle （AuNPs）, the fluorescence was quenched. AChE can break down acetylthiocholine to produce a thiol-bearing compound, thiocholine. In the presence of thiocholine, the nile red is replaced from the AuNPs sur- faces and simultaneously transformed to a derivative of nile red. The fluorescence intensity of the derivative is much stronger than that of the native nile red with the same concentration and its maximum emission wavelength has a blue shift so that the sensor achieves a good signal-to-background ratio. In addition, when organophosphate pesticide （OPs） exists, the activity of AChE can be inhibited, the generation of thiocholine will be prevented and no fluorescence enhancement occurs. The results show that the method is sensitive to AChE and paraoxon with the de- tection limits of 0.2 mU/mL and 0.05 ng/mL, respectively.展开更多
文摘A new sensitive fluorometric assay method for acetylcholinesterase （ACHE） and its inhibitor was developed us- ing a fluorescent dye, nile red （NR）. Due to the fluorescence resonance energy transfer between the NR and the gold nanoparticle （AuNPs）, the fluorescence was quenched. AChE can break down acetylthiocholine to produce a thiol-bearing compound, thiocholine. In the presence of thiocholine, the nile red is replaced from the AuNPs sur- faces and simultaneously transformed to a derivative of nile red. The fluorescence intensity of the derivative is much stronger than that of the native nile red with the same concentration and its maximum emission wavelength has a blue shift so that the sensor achieves a good signal-to-background ratio. In addition, when organophosphate pesticide （OPs） exists, the activity of AChE can be inhibited, the generation of thiocholine will be prevented and no fluorescence enhancement occurs. The results show that the method is sensitive to AChE and paraoxon with the de- tection limits of 0.2 mU/mL and 0.05 ng/mL, respectively.
