Detection of Ag+ using graphite carbon nitride nanosheets based on fluorescence quenching

•A fluorescence probe with graphite carbon nitride nanosheets for Ag+ is fabricated.•The proposed method exhibits high sensitivity, short analysis time and wide linear range.•The quenching mechanism is briefly discussed.

The graphite carbon nitride (g-C3N4) nanosheets were synthesized and applied for the detection of Ag+ ion in aqueous solutions. Transmission electron microscopy, Fourier infrared spectroscopy, x-ray diffraction, ultraviolet/visible and photoluminescence spectroscopy were used for characterization of g-C3N4 nanosheets. The fluorescence intensity of g-C3N4 nanosheets decreases with the increase in the concentration of Ag+. The fluorescence probe can be applied for detection of Ag+. The results show that it has high selectivity to Ag+ and exhibits a good linearity over the concentration range 0.020–2.0 μM with a detection limit of 27 nM. Most cations do not have any interference on the detection of Ag+. The quenching process is assessed and discussed. Finally, the g-C3N4 nanosheets have been successfully used for the detection of Ag+ in real water samples. The recoveries of spiked water samples are > 97%.

Graphical abstractGraphite carbon nitride nanosheets (g-C3N4 nanosheets) were successfully synthesized by an ultrasonic exfoliation method from bulk g-C3N4 in aqueous medium. The g-C3N4 nanosheets is seriously quenched by Ag+. The fluorescence probe can be applied for detection of Ag+.Figure optionsDownload full-size imageDownload as PowerPoint slide