Sensitive detection of glucose in human serum with oligonucleotide modified gold nanoparticles by using dynamic light scattering technique.
Dynamic light scattering based sensor for glucose was developed with oligonucleotide functionalized gold nanoparticles (Oligo-AuNPs). Oligonucleotide 5'-SH-(A)(12)-AGACAAGAGAGG-3' (Oligo 1) modified AuNPs and oligonucleotide 5'-CAACAGAGAACG-(A)(12)-HS-3' (Oligo 2) modified AuNPs could hybridize with oligonulceotide 5'-CGTTCTCTGTTGCCTCTCTTGTCT-3' (Oligo 3), which resulted in the aggregation of Oligo-AuNPs probes, and triggered the increase of their average diameter. However, Oligo 3 could be cleaved into DNA fragments by the mixture of glucose, glucose oxidase (GOD) and Fe(2+), and the DNA fragments could not hybridize with Oligo-AuNPs probes. Under the conditions of 3.7 nM Oligo 1-AuNPs, 3.7 nM Oligo 2-AuNPs, 8.0 μg/mL GOD, 100 nM Oligo 3 and 900 nM Fe(2+), the average diameter of Oligo-AuNPs probes decreased linearly with the increasing concentration of glucose over the range from 50 pmol/L to 5.0 nmol/L, with a detection limit of 38 pmol/L (3σ/slope). Moreover, five sugars had no effect on the average diameter of mixture of Oligo-AuNPs probes, GOD and Fe(2+), which demonstrated the good selectivity of the assay.
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, PR China.
Xiangmin
X
Miao
Liansheng
L
Ling
Xintao
X
Shuai
D015374:Biosensing Techniques / Q000295:instrumentation*; D001786:Blood Glucose / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D009841:Oligonucleotides / Q000737:chemistry*; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity
D001786:Blood Glucose; D009841:Oligonucleotides; D006046:Gold