Influence of DNA concentration on the interfacial electrode impedance.
Sensitive and accurate DNA quantification is an essential step in most DNA analyses, especially in analysis of a small amount of DNA. Instead of typical DNA quantification methods (i.e., UV spectrometry, fluorometry, and quantitative polymerase chain reaction), electrical impedance spectroscopy has recently been investigated for label-free and efficient quantification of DNA. In this study, quantification of DNA in solution was investigated using electrical impedance spectroscopy without pre-processing, including the modification of the electrode surface and immobilization of DNA onto the electrode. The results showed that the measured impedance spectra were in agreement with a designed equivalent circuit model, and that the extrapolated parameters of interfacial electrode impedance were dependent on DNA concentration. The impedance measured at 1 and 10 kHz showed good correlation with DNA concentration (R2 > 0.95), with a dynamic range of detection from 0.01 pg/microl to 100 ng/microl. Based on the results, it is expected to utilize impedance spectroscopy for the real-time and label-free characterization of DNA concentration with high sensitivity and low operation cost.
Department of Biomedical Engineering, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon 406-799, Republic of Korea.
Sungbo
S
Cho
Younshin
Y
Oh
Sung-Min
SM
Ahn
D004247:DNA / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*; D058266:Dielectric Spectroscopy / Q000295:instrumentation* / Q000379:methods; D017097:Electric Impedance; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008832:Microchemistry / Q000295:instrumentation* / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties
D004247:DNA