Ratiometric luminescence detection of hydrazine with a carbon dots-hemicyanine nanohybrid system

It is significant to develop probes for rapid, selective, and sensitive detection of highly toxic hydrazine in both environmental and biological science. In this work, under mild conditions, through the electrostatic attraction between negatively charged CDs and positively charged hemicyanine molecules, a novel ratiometric fluorescent probe containing CDs and a hemicyanine derivative was fabricated for reliable, selective, and sensitive sensing of hydrazine. This nanohybrid system possesses dual emission peaks at 550 and 610 nm under a single excitation wavelength of 530 nm. The addition of hydrazine to CDshemicyanine nanohybrid solution results in complete fluorescence quenching of the hemicyanine derivative, while the orange fluorescence of CDs remains constant. Furthermore, the CDs-hemicyanine nanohybrid system shows high selectivity toward hydrazine over other various species, including some nucleophilic species, metal ions and anions. The limit of quantification (LOQ) was 0-1 mM and the detection limit was as low as 8.0 mu M.