The fluorescence monitoring of formaldehyde in real environmental samples and live plant tissues is of great importance for physiological and pathological studies. However, there is a lack of suitable chemical tools to directly trace and measure the formaldehyde activity in bio-systems, and developing effective and, in particular, selective sensors for mapping formaldehyde in live tissues still remains a great challenge. Here, we demonstrate for the first time that the ratiometric fluorescence monitoring of formaldehyde in live plant tissues is achieved with a newly developed ratiometric fluorescent probe, FAP, which effectively eliminated interference from other comparative analytes. Live tissue analyses reveal that FAP can potentially detect exogenous and endogenous formaldehyde in live Arabidopsis thaliana tissues, exposing a potential application for biological and pathological studies of formaldehyde.

We have developed a novel colorimetric and ratiometric fluorescence probe for the selective and sensitive monitoring of hydrogen sulfide based on a dicyanoisophorone platform. An excellent linear relationship of fluorescence intensity ratio (I637/I558) (R2 = 0.9867) versus hydrogen sulfide concentration in the range of 1–12 μM was obtained. This probe exhibited a remarkable fluorescence response to hydrogen sulfide over other physiological thiols or biological species, which fluoresces in the red region with a large Stokes shift (172 nm). This probe was successfully utilized to monitor H2S under in vitro physiological conditions and for imaging H2S in living cells and living zebrafish in vivo.

A naphthalimide-azide based colorimetric and ratiometric fluorescent probe, NAP-1, has been developed for the selective and sensitive detection of hydrogen sulphide. Advantages of the probe NAP-1 include a low detection limit (110 nM), good selectivity, high sensitivity and excellent photostability. A linear relationship between the emission intensity ratios and sulphide concentrations was observed in PBS buffer and bovine serum, respectively. Our probe facilitates ratiometric determination and imaging of endogenous H2S in living cells. Furthermore, this probe was successfully applied to the measurement of endogenous sulphide in human plasma and mouse hippocampus. A significant reduction in sulphide levels and CBS mRNA expression was observed in the hippocampus of mouse models of lipopolysaccharide-induced neuroinflammation-related diseases, suggesting that decreased levels of endogenous H2S might be involved in the pathogenesis of neuroinflammation-related neurodegenerative diseases.

•HFP was a novel selective, sensitive and colorimetric fluorescent probe for N2H4.•This probe shows a 117 nm red-shifted absorption spectra with addition of N2H4.•This probe can detect N2H4 in an aqueous solution by the fluorescence enhancement.•This probe can be used for imaging hydrazine in living cells.We report a novel colorimetric and red-emitting fluorescent probe for hydrazine detection based on resorufin platform. This OFF–ON fluorescent probe shows a large (117 nm) red-shifted absorption spectrum and the color changes from colorless to red upon addition of hydrazine in the aqueous solution, which can serve as a “naked-eye” probe for hydrazine. Moreover, this probe also shows a significant fluorescence increase (~16 folds) and excellent linear relationship at physiological pH. Utilizing this sensitive and selective probe, we have successfully detected hydrazine in living cells.

The fluorescence monitoring of formaldehyde in real environmental samples and live plant tissues is of great importance for physiological and pathological studies. However, there is a lack of suitable chemical tools to directly trace and measure the formaldehyde activity in bio-systems, and developing effective and, in particular, selective sensors for mapping formaldehyde in live tissues still remains a great challenge. Here, we demonstrate for the first time that the ratiometric fluorescence monitoring of formaldehyde in live plant tissues is achieved with a newly developed ratiometric fluorescent probe, FAP, which effectively eliminated interference from other comparative analytes. Live tissue analyses reveal that FAP can potentially detect exogenous and endogenous formaldehyde in live Arabidopsis thaliana tissues, exposing a potential application for biological and pathological studies of formaldehyde.

A naphthalimide-azide based colorimetric and ratiometric fluorescent probe, NAP-1, has been developed for the selective and sensitive detection of hydrogen sulphide. Advantages of the probe NAP-1 include a low detection limit (110 nM), good selectivity, high sensitivity and excellent photostability. A linear relationship between the emission intensity ratios and sulphide concentrations was observed in PBS buffer and bovine serum, respectively. Our probe facilitates ratiometric determination and imaging of endogenous H2S in living cells. Furthermore, this probe was successfully applied to the measurement of endogenous sulphide in human plasma and mouse hippocampus. A significant reduction in sulphide levels and CBS mRNA expression was observed in the hippocampus of mouse models of lipopolysaccharide-induced neuroinflammation-related diseases, suggesting that decreased levels of endogenous H2S might be involved in the pathogenesis of neuroinflammation-related neurodegenerative diseases.