Immobilization, hybridization and amperometric detection of DNA sensor using quartz crystal microbalance.
A synthesized 21-mer single-stranded DNA (ssDNA) was covalently immobilized onto a self-assembled aminoethanethiol monolayer modified gold electrode onto quartz crystal microbalance (QCM). The covalently immobilized ssDNA was hybridized with complementary ssDNA. The interaction between surface-immobilized ssDNA and complementary 21-mer DNA in solution was also examined. Each step was followed by monitoring changes in the QCM frequency over time. From the results, the measured frequency change was about 256 Hz, 160 Hz and 141 Hz, respectively. As a result, the adsorption mass was about 273 ng/cm2, 171 ng/cm2 and 151 ng/cm2, according to the Sauerbrey equation. Also, PBS with pH 7.0 was selected as a supporting electrolyte to achieve maximum sensitivity and good bioactivity. The anodic peak current was linearly related to the concentrations between 1 x 10(-5) and 9 x 10(-5) M with a detection limit of 1.0 x 10(-6) M.
Lee
Dong-Yun
DY
Department of Electrical Engineering and NTRC, Dong-A University, Busan 604-714, Korea.
Choi
Won-Suk
WS
Kafi
A K M
AK
Park
Sang-Hyun
SH
Kwon
Young-Soo
YS
D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D002138:Calibration; D003460:Crystallization; D004247:DNA / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D004573:Electrolytes; D006863:Hydrogen-Ion Concentration; D036103:Nanotechnology / Q000379:methods; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry; D011791:Quartz
D004277:DNA, Single-Stranded; D004573:Electrolytes; D009841:Oligonucleotides; D011791:Quartz; D004247:DNA