|
Nanocatalytic Resonance Rayleigh Scattering Determination of Trace Hemin Using Aptamer-Modified Nanogold Probe
DONG Jin-chao, WEN Gui-qing, LIU Qing-ye, LIANG Ai-hui, JIANG Zhi-liang
Journal of Guangxi Normal University(Natural Science Edition). 2013, 31 (3):
191-196.
Hemin aptamer was used to modify gold nanoparticles (AuNPs) to obtain a stable aptamer-nanogold probe (AussDNA).In the condition of pH8.0 Tris-HCl buffer solution containing 50 mmol/L NaCl,the substrate chain of AussDNA was cracked by hemin to produce a short single-stranded DNA (ssDNA) and then further combine with hemin to form a stable hemin-ssDNA conjugate.The AuNPs released from AussDNA would be aggregated in the condition of 50 mmol/L NaCl and exhibited a strong resonance Rayleigh scattering (RRS) peak at 367.6 nm.Under the selected conditions,the increased RRS intensity (ΔI367.6 nm) was linear to hemin concentration in the range of 5~750 nmol/L,with a regression equation of ΔI367.6 nm=2.4C-144.4,coefficient of 0.982 9,and 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 Cu2O particle reaction of Fehling reagent-glucose that can be monitored by RRS technique at 370 nm.When the hemin concentration increased,the AussDNA decreased,the catalysis decreased,and the RRS intensity at 370 nm decreased.The decreased RRS intensity ΔI370 nm was linear to the hemin concentration in the range of 0.25~200 nmol/L,with a regression equation of ΔI370 nm=5.5C+78,coefficient of 0.971 9,and a detection limit of 17 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.
References |
Related Articles |
Metrics
|