Microflow injection potassium bioassay based on G-quadruplex DNAzyme-enhanced chemiluminescence.
By taking advantage of microflow injection chemiluminescence analysis, we developed a distinctive microfluidic bioassay method based on G-Quadruplex DNAzyme-enhanced chemiluminescence for the determination of K(+) in human serum. AGRO100, the G-rich oligonucleotide with high hemin binding affinity was primarily selected as a K(+) recognition element. In the presence of K(+), AGRO100 folded into G-quadruplex and bound hemin to form DNAzyme, which catalyzed the oxidation of luminol by H2 O2 to produce chemiluminescence. The intensity of chemiluminescence increased with the K(+) concentration. In the study, the DNAzyme showed both long-term stability and high catalytic activity; other common cations at their physiological concentration did not cause notable interference. With only 6.7 × 10(-13) mol of AGRO100 consumption per sample, a linear response of K(+) ranged from 1 to 300 µmol/L, the concentration detection limit 0.69 µmol/L (S/N = 3) and the absolute detection limit 1.38 × 10(-12) mol were obtained. The precision of 10 replicate measurements of 60 µmol/L K(+) was found to be 1.72% (relative standard deviation). The accuracy of the method was demonstrated by analyzing real human serum samples.
Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou, People's Republic of China.
Lifang
L
Song
Xiaoyan
X
Pan
Hong
H
Shen
Yaling
Y
Yu
D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic / Q000737:chemistry / Q000378:metabolism; D004867:Equipment Design; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods*; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D008165:Luminol / Q000737:chemistry / Q000378:metabolism; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D009838:Oligodeoxyribonucleotides / Q000378:metabolism; D011188:Potassium / Q000097:blood*; D015203:Reproducibility of Results
C513936:AGRO 100; D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D009838:Oligodeoxyribonucleotides; D008165:Luminol; D006427:Hemin; D006861:Hydrogen Peroxide; D011188:Potassium
DNAzyme; chemiluminescence; microflow injection; potassium ion