压电DNA传感器检测模式对频率漂移的影响

Influence of Measurement Modes on Frequency Drifts in Piezoelectricity DNA Detection

利用分子自组装技术将DNA探针固定在石英金膜表面与生物素标记的靶DNA杂交,再结合经40 nm胶体金标记的亲核素,放大检测频率以提高检测灵敏度。靶DNA质量经胶体金放大后,QCM的频率降达到了86 Hz,其检出限可达10 fmol/L。在其检测过程中,分别考察了裸DNA晶片直接检测和晶片组装在底座中检测两种模式。前者由于杂交液扩散和溶液挥发,易造成频率检测不稳定和失真,后者由于避免了溶液扩散和挥发,能有效提高频率检测的稳定性和准确度。

HS-DNA probe was immobilized on the gold surface of quartz crystal oscillator by selfassembling. After hybridization, target DNA was connected with 40 nm Au nanoparticle via biotinstreptavidin conjugation to enlarge the frequency change and improve the sensitivity of detection. The frequency change reached to 86 Hz and the detection limit reached to 10 fmol/L in our experiments. Two measurement modes-naked crystal measurement and holder equipment mode were investigated. It was found that the frequency measurement was unstable and distorted under the former mode due to the diffusion of hybridization solution and the volatilization of buffer solution. However, this situation did not appear under the latter mode, which could ensure the stability and accuracy of the frequency measurement effectively.