The spatiotemporal sensing of specific cationic and anionic species is crucial for understanding the processes occurring in living systems. Herein, we developed new fluorescence sensors derived from tetrapyrazinoporphyrazines (TPyzPzs) with a recognition moiety that consists of an aza-crown and supporting substituents. Their sensitivity and selectivity were compared by fluorescence titration experiments with the properties of known TPyzPzs (with either one aza-crown moiety or two of these moieties in a tweezer arrangement). Method of standard addition was employed for analyte quantification in saliva. For K+ recognition, the new derivatives had comparable or larger association constants with larger fluorescence enhancement factors compared to that with one aza-crown. Their fluorescence quantum yields in the ON state were 18× higher than that of TPyzPzs with a tweezer arrangement. Importantly, the sensitivity toward cations was strongly dependent on counteranions and increased as follows: NO3- < Br- < CF3SO3- < ClO4- ≪ SCN-. This trend resembles the chaotropic ability expressed by the Hofmeister series. The high selectivity toward KSCN was explained by synergic association of both K+ and SCN- with TPyzPz sensors. The sensing of SCN- was further exploited in a proof of concept study to quantify SCN- levels in the saliva of a smoker and to demonstrate the sensing ability of TPyzPzs under in vitro conditions.
- MeSH
- crown ethery chemická syntéza chemie MeSH
- draslík analýza MeSH
- fluorescence MeSH
- fluorescenční barviva chemická syntéza chemie MeSH
- fluorescenční mikroskopie metody MeSH
- fluorescenční spektrometrie metody MeSH
- HeLa buňky MeSH
- kuřáci MeSH
- lidé MeSH
- limita detekce MeSH
- metaloporfyriny chemická syntéza chemie MeSH
- sliny chemie MeSH
- thiokyanatany analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- anabasin analogy a deriváty moč MeSH
- biologické markery analýza chemie MeSH
- inhalační expozice analýza MeSH
- kouření cigaret * škodlivé účinky MeSH
- lidé MeSH
- nikotin analýza krev metabolismus MeSH
- oxid uhelnatý metabolismus MeSH
- tabákové výrobky MeSH
- thiokyanatany analýza krev MeSH
- vystavení vlivu životního prostředí MeSH
- znečištění tabákovým kouřem analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
An automated, simple and inexpensive double-valve sequential injection analysis (DV-SIA) spectrophotometic method with online liquid-liquid extraction, for the determination of thiocyanate has been developed. The method has been based on the formation of an ion associate between thiocyanate and Astra Phloxine in acidic medium, and the subsequent extraction with amylacetate. The absorbance of the extracted ion associate was measured at 550nm. The calibration function was linear in the range 0.05-0.50mmolL(-1) and the regression equation was A=(1.887±0.053) [SCN(-)mmolL(-1)]+(0.037±0.014) with a correlation coefficient of 0.995. The precision of the proposed method was evaluated by the relative standard deviation (RSD) values at two concentration levels: 0.20 and 0.50mmolL(-1). The obtained results were 1.0 and 2.8%, respectively, for the intra-day precision, and 4.2 and 3.8%, respectively for the inter-day precision. The calculated detection limit was 0.02mmolL(-1). The developed method has been successfully applied for determining thiocyanate ions in human saliva samples.
- MeSH
- indoly chemie MeSH
- kalibrace MeSH
- lidé MeSH
- limita detekce MeSH
- průtoková injekční analýza metody MeSH
- sliny chemie MeSH
- thiokyanatany analýza chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Infection by Pseudomonas aeruginosa (PA) is a major cause of morbidity and mortality in patients with cystic fibrosis (CF). Breath analysis could potentially be a useful diagnostic of such infection, and analyses of volatile organic compounds (VOCs) emitted from PA cultures are an important part of the search for volatile breath markers of PA lung infection. Our pilot experiments using solid-phase microextraction, SPME and gas chromatography/mass spectrometric (GC/MS) analyses of volatile compounds produced by PA strains indicated a clear presence of methyl thiocyanate. This provided a motivation to develop a method for real-time online quantification of this compound by selected ion flow tube mass spectrometry, SIFT-MS. The kinetics of reactions of H(3)O(+), NO(+) and O(2)(+•) with methyl thiocyanate at 300 K were characterized and the characteristic product ions determined (proton transfer for H(3)O(+), rate constant 4.6 × 10(-9) cm(3) s(-1); association for NO(+), 1.7 × 10(-9) cm(3) s(-1) and nondissociative charge transfer for O(2)(+•) 4.3 × 10(-9) cm(3) s(-1)). The kinetics library was extended by a new entry for methyl thiocyanate accounting for overlaps with isotopologues of hydrated hydronium ions. Solubility of methyl thiocyanate in water (Henry's law constant) was determined using standard reference solutions and the linearity and limits of detection of both SIFT-MS and SPME-GC/MS methods were characterized. Thirty-six strains of PA with distinct genotype were cultivated under identical conditions and 28 of them (all also producing HCN) were found to release methyl thiocyanate in headspace concentrations greater than 6 parts per billion by volume (ppbv). SIFT-MS was also used to analyze the breath of 28 children with CF and the concentrations of methyl thiocyanate were found to be in the range 2-21 ppbv (median 7 ppbv).
- MeSH
- biologické markery analýza MeSH
- cystická fibróza metabolismus mikrobiologie MeSH
- dechové testy metody MeSH
- dítě MeSH
- hmotnostní spektrometrie metody MeSH
- lidé MeSH
- mikroextrakce na pevné fázi metody MeSH
- mladiství MeSH
- mladý dospělý MeSH
- předškolní dítě MeSH
- pseudomonádové infekce komplikace metabolismus MeSH
- Pseudomonas aeruginosa metabolismus MeSH
- reprodukovatelnost výsledků MeSH
- thiokyanatany analýza MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This paper describes a method for the determination of cyanide using in-capillary enzymatic reaction with rhodanese. Poorly absorbing cyanide is in rhodanese reaction transformed into highly absorbing thiocyanate that is further separated by capillary electrophoresis (CE) and determined spectrophotometrically at 200 nm. Cyanide is thus estimated indirectly from the result of thiocyanate quantification and moreover, it can be easily determined with sufficient sensitivity by means of CE apparatus equipped with common UV detector. The linear detection range for concentration versus peak area for the assay is from 15 to 500 microM (correlation coefficient 0.997) with a detection limit of 3 microM and a limit of quantitation 9 microM. The inter-day reproducibility of the peak area was below 3.2% and the inter-day reproducibility of the migration time below 0.1%. The method is relatively rapid, simple and can be easily automated. Moreover, only limited amount of the sample is required.
