Highly sensitive and selective “off-on” fluorescent sensing platform for ClO− in water based on silicon quantum dots coupled with nanosilver
We present a new “off-on” fluorescence probe for detecting hypochlorite (ClO−) based on silicon quantum dots coupled with silver nanoparticles (SiQDs/AgNPs) as nanocomplexes. Via introducing N-[3-(trimethoxysilyl)propyl]ethylenediamine and catechol as initial reactants, silicon quantum dots (SiQDs) with excellent properties were synthesized through a simple hydrothermal method. Transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the morphology and structure of quantum dots. The fluorescence of SiQDs could be quenched by the silver nanoparticles (AgNPs) by surface plasmon-enhanced energy transfer (SPEET) from SiQDs (donor) to AgNPs (acceptor). The AgNPs could be etched by adding ClO−, thus freeing the SiQDs from the AgNP surfaces and restoring the SiQDs’ fluorescence. The sensing system exhibits many advantages, such as wide linear response range, high sensitivity, and excellent selectivity. Under optimized conditions, wide linear ranges (from 0.1 to 100.0 μM) and low detection limits (0.08 μM) were obtained for ClO−.
KeywordsClO− Silicon quantum dots Silver nanoparticles Probe Fluorescence
This study received support from the National Natural Science Foundation of China (21607061), the Opening Project of State Key Laboratory of Chemo/Biosensing and Chemometrics of Hunan University (2016017), the Priority Academic Program Development of Jiangsu Higher Education Institutions, the Collaborative Innovation Center of Technology and Material of Water Treatment, and the Program of Young Backbone Teachers in Jiangsu University (2015).
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Conflict of interest
The authors declare that they have no conflicts of interest.
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