RESUMEN
A wireless magnetoelastic sensor has been developed for the determination of 2-naphthol (2-NAP) in human urine. This method is based on the precipitation of 2-NAP with diazonium salts produced by the diazo-reaction of sulfamethoxazole (SMZ) with nitrite under a weak alkaline condition, resulting in a descending of the resonance frequency of a wireless magnetoelastic sensor. The frequence shift values (ΔF) of the sensor were directly proportional to the concentration in the range of 1.13 - 139 µmol L(-1) for 2-NAP with a correlation coefficient of 0.997 and a detection limit of 0.340 µmol L(-1). The relative standard deviations were 2.38, 2.40 and 2.44%, and the average recovery was 107% (n = 6). The proposed method has additional advantages of being less time-consuming, low cost and remote query, and can be applied for real-time and in situ monitoring of 2-NAP in human urine. It would be a benefit to extend the scope of applications of magnetoelastic sensing techniques.
Asunto(s)
Compuestos Azo/química , Técnicas Biosensibles/instrumentación , Magnetismo , Naftoles/orina , Elasticidad , Humanos , Estructura Molecular , Sales (Química)/química , Sensibilidad y EspecificidadRESUMEN
A novel method of first derivative synchronous fluorescence was developed for the rapid simultaneous analysis of trace 1-hydroxypyrene (1-OHP), 1-naphthol (1-NAP), 2-naphthol (2-NAP), 9-hydroxyphenanthrene (9-OHPe) and 2-hydroxyfluorene (2-OHFlu) in human urine. Only one single scan was needed for quantitative determination of five compounds simultaneously when Deltalambda=10 nm was chosen. In the optimal experimental conditions, there was a linear relationship between the fluorescence intensity and the concentration of 1-OHP, 1-NAP, 2-NAP, 9-OHPe and 2-OHFlu in the range of 1.75 x 10(-9) to 4.50 x 10(-6) mol L(-1), 3.64 x 10(-8) to 2.20 x 10(-4) mol L(-1), 8.18 x 10(-9) to 1.20 x 10(-4) mol L(-1), 3.26 x 10(-9) to 8.50 x 10(-5) mol L(-1) and 4.88 x 10(-9) to 5.50 x 10(-6) mol L(-1), respectively. The limits of detection (LOD) were found to be 5.25 x 10(-10) mol L(-1) for 1-OHP, 1.10 x 10(-8) mol L(-1) for 1-NAP, 2.46 x 10(-9) mol L(-1) for 2-NAP, 9.77 x 10(-10) mol L(-1) for 9-OHPe and 1.46 x 10(-9) mol L(-1) for 2-OHFlu. The proposed method is reliable, selective and sensitive, and has been used successfully in the determination of traces of 1-OHP, 1-NAP, 2-NAP, 9-OHPe and 2-OHFlu in human urine samples, whose results were in good agreement with those gained by the HPLC method.
Asunto(s)
Hidrocarburos Policíclicos Aromáticos/orina , Polisorbatos/química , Espectrometría de Fluorescencia/métodos , Tensoactivos/química , Fluorenos/orina , Humanos , Concentración de Iones de Hidrógeno , Naftoles/orina , Fenantrenos/orina , Hidrocarburos Policíclicos Aromáticos/química , Pirenos/análisisRESUMEN
A novel sensitive method has been developed for the detection of adenosine (AD) in human urine by using enhanced resonance light scattering (RLS). This method is based on the specific recognition and signal amplification of adenosine aptamer (Apt) coupled with gold nanoparticles (GNPs) via G-quartet-induced nanoparticle assembly, which was fabricated by triggering a structure switching of the 3' terminus G-rich sequence and aptamer duplex. RLS signal linearly correlated with the concentration of adenosine over the range of 6-115nM. The limit of detection (LOD) for adenosine is 1.8nM with relative standard deviations (RSD) of 2.90-4.80% (n=6). The present method has been successfully applied to determination of adenosine in real human urine, and the obtained results were in good agreement with those obtained by the HPLC method. Our investigation shows that the combination of the excellent selectivity of aptamer with the high sensitivity of the RLS technique could provide a promising potential for aptamer-based small molecule detection, and be beneficial in extending the application of RLS.
Asunto(s)
Adenosina/orina , Oro/química , Nanopartículas del Metal/química , Aptámeros de Nucleótidos/química , Humanos , Concentración de Iones de Hidrógeno , Luz , Límite de Detección , Técnica SELEX de Producción de Aptámeros , Dispersión de Radiación , Espectrometría de Fluorescencia , TemperaturaRESUMEN
A novel method for the simultaneous determination of 1-hydroxypyrene (1-OHP), beta-naphthol (beta-NAP) and 9-hydroxyphenanthrene (9-OHPe) in human urine has been established by using synchronous fluorescence spectrometry. It was based on the fact that synchronous fluorescence spectrometry can resolve the broad-band overlapping of conventional fluorescence spectra, which arise from their similar molecular structures. Only one single scan is needed for quantitative determination of three compounds simultaneously when Deltalambda=15nm is chosen. The signals detected at these three wavelengths, 369.6, 330.0 and 358.0nm, vary linearly when the concentration of 1-OHP, beta-NAP and 9-OHPe is in the range of 2.16x10(-8)-1.50x10(-5)molL(-1), 1.20x10(-7)-1.10x10(-5)molL(-1) and 1.07x10(-7)-3.50x10(-5)molL(-1), respectively. The correlation coefficients for the standard calibration graphs were 0.994, 0.999 and 0.997 (n=7) for 1-OHP, beta-NAP and 9-OHPe, respectively. The limits of detection (LOD) for 1-OHP, beta-NAP and 9-OHPe were 6.47x10(-9)molL(-1), 3.60x10(-8)molL(-1) and 3.02x10(-8)molL(-1)with relative standard deviations (R.S.D.) of 4.70-6.40%, 2.80-4.20%, 3.10-4.90% (n=6), respectively. The method described here had been applied to determine traces of 1-OHP, beta-NAP and 9-OHPe in human urine, and the obtained results were in good agreement with those obtained by the HPLC method. In addition, the interaction modes between beta-cyclodextrin (beta-CD) and 1-OHP, beta-NAP or 9-OHPe, as well as the mechanism of the fluorescence enhancement were also discussed.