A dual-channel "on-off-on" fluorescent probe for the detection and discrimination of Fe3+ and Hg2+ in piggery feed and swine wastewater.

ABSTRACT

Blue-fluorescent blood-CDs were synthesized through a one-pot hydrothermal method using a mixture of chicken blood and trisodium citrate and then explored as a fluorescent probe for detecting Fe3+ and Hg2+. The probe showed excellent selectivity and sensitivity towards Fe3+ and Hg2+ with a dramatic "on-off" fluorescence response. F- recovered the fluorescence quenching by Fe3+, and Al3+ recovered the fluorescence quenching by Hg2+, showing an "off-on" fluorescence response. The blood-CDs were used as an "on-off-on" dual-channel fluorescent sensor for the detection and discrimination of Fe3+ and Hg2+ ions. The probe showed wide linear ranges for determination of Fe3+ (0-100 µM) and Hg2+ (0-120 µM) with low detection limits of 0.23 µM for Fe3+ and 0.17 µM for Hg2+. This probe was practically applied for the determination of Fe3+ and Hg2+ in piggery feed and wastewater with good recoveries. This work provides a fluorescent probe for the quantification of Fe3+ and Hg2+ in livestock feed and environmental water samples.