A fluorescent probe using phosphorus-doped graphite carbon nitride nanosheets for the detection of silver ions and cell imaging

Abstract

The fluorescent phosphorus-doped graphite carbon nitride (P-g-C3N4) nanosheets have been synthesized as a fluorescence probe using an ultrasonic exfoliating method. The as-prepared P-g-C3N4 nanosheets were characterized by multiple analytical techniques such as transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and infrared spectroscopy. The fluorescence intensity of P-g-C3N4 nanosheets decreases with the increase in concentration of silver ions. A good linear relationship was achieved between the corresponding fluorescence intensity of P-g-C3N4 nanosheets and the concentration of silver ions in the range of 20 nmol/L – 3.2 μmol/L. The quenching mechanism of interaction between P-g-C3N4 nanosheets and silver ions was primarily discussed. The proposed fluorescence probe has been successfully applied to detect silver ions in real water samples and the recoveries range from 96.8% to 103.7%.