RESUMEN
Based on the AuNPs/Nafion composite membrane technology and immobilization of amino adenosine aptamer using carboxyl carbon nanotubes on the surface of a glassy carbon electrode, a electrochemiluminescence sensor was preparated.The sensor was characterized by cyclic voltammetry and electrochemical luminescence.The result showed that the sensor had a good stability and reproducibility.Adenosine and adenosine aptamer could form G-tetrahedral structure, leading a decrease of ECL intensity.Under the optimum experimental conditions, the relative ECL intensity showed a good linear relationship to the negative logarithm of adenosine concentration in the range of 1.0×10-11-1.0×10-7 mol/L, the linear equations was ΔIECL=-890lgC-5050 with a detection limit of 5.0×10-12 mol/L.The RSD was 2.7% in 11 times measurement of adenosine (1.0×10-10 mol/L).The recovery was 97.1%-110.0% in the determination of real adenosine sample.
RESUMEN
Chitosan-Ru ( bpy ) 2+3 -SiO2 composite nanoparticles ( CRuS NPs ) were prepared by reverse microemulsion method, and based on the Nafion/MCNT composite membrane technology, CRuS NPs were effectively and steadily immobilize on the surface of a glassy carbon electrode to prepare the electrochemiluminescence sensor for uric acid determination. In 0. 1 mol/L PBS (pH 7. 4) buffer solution, when the actuation duration between uric acid and the modified electrode was 15 min, the electrochemiluminescence showed a good linear relationship to the negative logarithm of uric acid concentration in the range of 1. 0 × 10-10-1. 0 × 10-5 mol/L, the linear equation was IECL=-709. 52-202. 74lgC and the correlation coefficient was 0. 9936 with a detection limit of 6. 0 × 10-12 mol/L. The ECL sensor exhibited excellent repeatability and stability, and the RSD for 11 times determination of 1. 0 × 10-8 mol/L uric acid was 2. 9%. The recovery was 98. 5%-103. 5% in the determination of real Uric acid sample.
RESUMEN
Poly ( aniline_luminol ) composite nanowires were synthesized by chemical oxidation using ammonium peroxydisulfate. In contrast to the maximum fluorescence emitting wavelength of luminol at 425 nm, the maximum fluorescence emitting wavelength of the polymeric luminol in the composite nanowires was red shifted to 465 nm obviously. The poly ( aniline_luminol) composite nanowires were modified on graphite electrode surface by drop coating, forming a stable poly ( aniline_luminol ) composite nanowires film. The composite nanowires film modified electrode presented favorable electrochemiluminescence ( ECL ) performances, and the ECL response could be enhanced by hydrogen peroxide. Under the optimized experimental conditions, the modified electrode provided a linear range of 5. 0×10-9-1. 0×10-5 mol/L for the detection of hydrogen peroxide with a detection limit of 2 ×10-9 mol/L.
RESUMEN
A new closed bipolar electrode electrochemiluminescence ( ECL)-based device was designed, and further used to investigate the ECL behaviors of luminol in this device. Our results showed that, while a suitable voltage was applied to the two poles of the closed bipolar electrode, both the positively charged ions and luminol-based anionic ions could be enriched on the two poles of the closed bipolar electrode, respectively. More importantly, the ECL signals, generated from the electro-oxidation of luminol on anodic pole, were found to be related to the total amount of positively charged ions on the cathodic pole of the closed bipolar electrode. Under the optimum experimental conditions, the ECL response was linearly to the concentration of analyte in the range of 1. 0×10-9-1. 0×10-8 mol/L with a detecting limit of 1. 1×10-10 mol/L. Based on this finding, a new ECL method for sensing the solution conductance was developed.
