A new amine moiety-based near-infrared fluorescence probe for detection of formaldehyde in real food samples and mice

A new amine moiety-based near-infrared fluorescent probe (Probe-NH2) is developed for detection of formaldehyde in food samples and mice. Probe-NH2 is constructed and synthesized from the IR-780 via two-step reactions as a hemicyanine skeleton bearing an amino moiety. The response mechanism is based on Schiff base reaction that formaldehyde reacts with amine group to form the corresponding imines. Probe-NH2 for detection of formaldehyde exhibits excellent analytical performance, including near-infrared fluorescence emission at 708 nm, high selectivity and sensitivity, also provides a response time as low as 30 min with a detection limit of 1.87 μmolL-1. Notably, we constructed a simple, rapid and visual formaldehyde detection platform based on paper chips in the near-infrared region for the first time. The accurate detection of formaldehyde in real food samples is of great significance, Probe-NH2 was detected in dried beancurd sticks, endive sprout, frozen shrimp and squid, with good recoveries of 99.60%-112.72%, indicating the reliability of Probe-NH2 for spiked determination of formaldehyde in contaminated foods. More importantly, Probe-NH2 has been successfully applied to the detection of endogenous formaldehyde in mice.