Absorption, Fluorescence and Resonance Rayleigh Scattering Spectra of Interaction of Papain with Calf Thymus DNA

2011 ◽  
Vol 29 (4) ◽  
pp. 822-828 ◽  
Author(s):  
Ling Kong ◽  
Zhongfang Liu ◽  
Xiaoli Hu ◽  
Shaopu Liu
Keyword(s):  
Rayleigh Scattering ◽  
Calf Thymus Dna ◽  
Resonance Rayleigh Scattering ◽  
Calf Thymus ◽  
Scattering Spectra

Resonance Rayleigh Scattering Determination of Trace Hemin Basing on Aptamer-Modified Nanogold Catalysis of HAuCl4-Vitamine C

2013 ◽  
Vol 787 ◽  
pp. 400-403
Author(s):  
Jin Chao Dong ◽  
Ai Hui Liang ◽  
Zhi Liang Jiang
Keyword(s):  
Detection Limit ◽  
Rayleigh Scattering ◽  
Resonance Rayleigh Scattering ◽  
Serum Samples ◽  
Buffer Solution ◽  
Strong Resonance ◽  
Scattering Spectra ◽  
Vitamine C ◽  
Nanogold Catalysis

Hemin aptamer was used to modify gold nanoparticles (AuNPs) to obtain a stable aptamer-nanogold probe (AussDNA). In the condition of pH 8.0 Tris-HCl buffer solution containing 50mmol/L NaCl, the substrate chain of AussDNA was cracked by hemin to produce a short single-stranded DNA(ssDNA) and then further combined with hemin to form a stable hemin-ssDNA conjugate. The AuNPs released from AussDNA would be aggregated in the condition of 50mmol/L NaCl and exhibited a strong resonance Rayleigh scattering (RRS) peak at 368nm. Under the selected conditions, the increased RRS intensity (ΔI368nm) was linear to hemin concentration in the range of 5-750nmol/L, with a detection limit of 66 pmol/L. This RRS method was applied to determination of residual hemin in serum samples, with satisfactory results. The remnant AussDNA in the solution exhibited a strong catalytic activity on the gold particle reaction of HAuCl4-vitamine C (VC) that can be monitored by RRS technique at 368 nm. When the hemin concentration increased, the AussDNA decreased, the catalysis decreased, and the RRS intensity at 368nm decreased. The decreased RRS intensity ΔI368nmwas linear to the hemin concentration in the range of 1-200nmol/L, with a detection limit of 54 pmol/L. Accordingly, a sensitivity, selectivity, and simplicity new method of resonance Rayleigh scattering spectra to detect hemin using aptamer-modified nanogold as catalyst was established.

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