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Highly selective fluorescent and colorimetric probe for live-cell monitoring of sulphide based on bioorthogonal reaction.

Huo FJ, Kang J, Yin C, Chao J, Zhang Y - Sci Rep (2015)

Bottom Line: To better understand its physiological and pathological functions, efficient methods for monitoring of H2S are desired.In the presence of H2S, however, a significant enhancement for excited fluorescence were observed, resulting in a high sensitivity to H2S in buffered (10 mmol/L HEPES, pH 7.0) aqueous acetonitrile solution (H2O/CH3CN = 1:3, v/v) with a detection limit of 0.035 μmol/L observed, much lower than the previously reported probes.All these features are favorable for direct monitoring of H2S with satisfactory sensitivity, demonstrating its value of practical application.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Applied Chemistry, Shanxi University, Taiyuan. 030006, China.

ABSTRACT
H2S is the third endogenously generated gaseous signaling compound and has also been known to involve a variety of physiological processes. To better understand its physiological and pathological functions, efficient methods for monitoring of H2S are desired. Azide fluorogenic probes are popular because they can take place bioorthogonal reactions. In this work, by employing a fluorescein derivative as the fluorophore and an azide group as the recognition unit, we reported a new probe 5-azidofluorescein for H2S with improved sensitivity and selectivety. The probe shows very low background fluorescence in the absence of H2S. In the presence of H2S, however, a significant enhancement for excited fluorescence were observed, resulting in a high sensitivity to H2S in buffered (10 mmol/L HEPES, pH 7.0) aqueous acetonitrile solution (H2O/CH3CN = 1:3, v/v) with a detection limit of 0.035 μmol/L observed, much lower than the previously reported probes. All these features are favorable for direct monitoring of H2S with satisfactory sensitivity, demonstrating its value of practical application.

No MeSH data available.


Related in: MedlinePlus

(a) Fluorescence spectra of probe (1 μmol/L) with various analytes (20 μmol/L) in water:CH3CN (1:3 v/v, HEPES buffer, pH 7.0) solutions (λex = 425 nm, slit: 5 nm/5 nm), inset: a visual fluorescence change photograph for H2S (green) and other analytes (colorless) under illumination with a 365 nm UV lamp; (b) Relative fluorescent intensity (λex = 425 nm, λem = 531 nm) of the system. (black bar: various analytess, red bar: probe + various analytes + H2S).
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f2: (a) Fluorescence spectra of probe (1 μmol/L) with various analytes (20 μmol/L) in water:CH3CN (1:3 v/v, HEPES buffer, pH 7.0) solutions (λex = 425 nm, slit: 5 nm/5 nm), inset: a visual fluorescence change photograph for H2S (green) and other analytes (colorless) under illumination with a 365 nm UV lamp; (b) Relative fluorescent intensity (λex = 425 nm, λem = 531 nm) of the system. (black bar: various analytess, red bar: probe + various analytes + H2S).

Mentions: Reaction of probe (1 μmol/L) with Na2S (2 μmol/L) as an aqueous sulphide source at room temperature in buffered (10 mmol/L HEPES, pH 7.0) aqueous acetonitrile solution (H2O/CH3CN = 1:3, v/v) yielded a time-dependent fluorescence increase, which was completed within 5 s (Supplementary Fig. S2). ΔF > 50-fold increase in the fluorescence intensity accompanied (Φ = 0.35) with a green emission at 531 nm. However, the analytes without hydrogen sulfide induced no changes in the fluorescence emission properties under the same conditions (Fig. 2a). The competing experiments indicated other analytes did not disturb the determination for sulphide (Fig. 2b). It is noted that the unprecedented speed of this probe's response and high selectivity compared with other probes35363738 suggests the possibility of quantitative detection without the need for sample pretreatment. The results reason that H2S-mediated reduction of azides to amines would generate highly fluorescent products (Fig. 3)39. H2S-induced product was confirmed its molecular formula by electrospray ionization mass spectrometry (ESI-MS). The peak at m/z 346.42 corresponding to [5-aminofluorescein-H]+, was clearly observed (Supplementary Fig. S3). Further 1HNMR spectroscopic analysis also provided the evidence for the product of 5-aminofluorescein. With addition of 2 equiv. of Na2S (containing crystal water) to probe in DMSO-d6 (Fig. S4), the resonance of the original proton (azidebenzene CH) at 7.28 and 7.49 ppm all shifted to upfield owing to presence of electron- pushing group NH2 (Supplementary Fig. S4) and appeared at 6.65 ~ 6.76 ppm.


Highly selective fluorescent and colorimetric probe for live-cell monitoring of sulphide based on bioorthogonal reaction.

Huo FJ, Kang J, Yin C, Chao J, Zhang Y - Sci Rep (2015)

(a) Fluorescence spectra of probe (1 μmol/L) with various analytes (20 μmol/L) in water:CH3CN (1:3 v/v, HEPES buffer, pH 7.0) solutions (λex = 425 nm, slit: 5 nm/5 nm), inset: a visual fluorescence change photograph for H2S (green) and other analytes (colorless) under illumination with a 365 nm UV lamp; (b) Relative fluorescent intensity (λex = 425 nm, λem = 531 nm) of the system. (black bar: various analytess, red bar: probe + various analytes + H2S).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4355735&req=5

f2: (a) Fluorescence spectra of probe (1 μmol/L) with various analytes (20 μmol/L) in water:CH3CN (1:3 v/v, HEPES buffer, pH 7.0) solutions (λex = 425 nm, slit: 5 nm/5 nm), inset: a visual fluorescence change photograph for H2S (green) and other analytes (colorless) under illumination with a 365 nm UV lamp; (b) Relative fluorescent intensity (λex = 425 nm, λem = 531 nm) of the system. (black bar: various analytess, red bar: probe + various analytes + H2S).
Mentions: Reaction of probe (1 μmol/L) with Na2S (2 μmol/L) as an aqueous sulphide source at room temperature in buffered (10 mmol/L HEPES, pH 7.0) aqueous acetonitrile solution (H2O/CH3CN = 1:3, v/v) yielded a time-dependent fluorescence increase, which was completed within 5 s (Supplementary Fig. S2). ΔF > 50-fold increase in the fluorescence intensity accompanied (Φ = 0.35) with a green emission at 531 nm. However, the analytes without hydrogen sulfide induced no changes in the fluorescence emission properties under the same conditions (Fig. 2a). The competing experiments indicated other analytes did not disturb the determination for sulphide (Fig. 2b). It is noted that the unprecedented speed of this probe's response and high selectivity compared with other probes35363738 suggests the possibility of quantitative detection without the need for sample pretreatment. The results reason that H2S-mediated reduction of azides to amines would generate highly fluorescent products (Fig. 3)39. H2S-induced product was confirmed its molecular formula by electrospray ionization mass spectrometry (ESI-MS). The peak at m/z 346.42 corresponding to [5-aminofluorescein-H]+, was clearly observed (Supplementary Fig. S3). Further 1HNMR spectroscopic analysis also provided the evidence for the product of 5-aminofluorescein. With addition of 2 equiv. of Na2S (containing crystal water) to probe in DMSO-d6 (Fig. S4), the resonance of the original proton (azidebenzene CH) at 7.28 and 7.49 ppm all shifted to upfield owing to presence of electron- pushing group NH2 (Supplementary Fig. S4) and appeared at 6.65 ~ 6.76 ppm.

Bottom Line: To better understand its physiological and pathological functions, efficient methods for monitoring of H2S are desired.In the presence of H2S, however, a significant enhancement for excited fluorescence were observed, resulting in a high sensitivity to H2S in buffered (10 mmol/L HEPES, pH 7.0) aqueous acetonitrile solution (H2O/CH3CN = 1:3, v/v) with a detection limit of 0.035 μmol/L observed, much lower than the previously reported probes.All these features are favorable for direct monitoring of H2S with satisfactory sensitivity, demonstrating its value of practical application.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Applied Chemistry, Shanxi University, Taiyuan. 030006, China.

ABSTRACT
H2S is the third endogenously generated gaseous signaling compound and has also been known to involve a variety of physiological processes. To better understand its physiological and pathological functions, efficient methods for monitoring of H2S are desired. Azide fluorogenic probes are popular because they can take place bioorthogonal reactions. In this work, by employing a fluorescein derivative as the fluorophore and an azide group as the recognition unit, we reported a new probe 5-azidofluorescein for H2S with improved sensitivity and selectivety. The probe shows very low background fluorescence in the absence of H2S. In the presence of H2S, however, a significant enhancement for excited fluorescence were observed, resulting in a high sensitivity to H2S in buffered (10 mmol/L HEPES, pH 7.0) aqueous acetonitrile solution (H2O/CH3CN = 1:3, v/v) with a detection limit of 0.035 μmol/L observed, much lower than the previously reported probes. All these features are favorable for direct monitoring of H2S with satisfactory sensitivity, demonstrating its value of practical application.

No MeSH data available.


Related in: MedlinePlus