Detection of Staphylococcus epidermidis by a Quartz Crystal Microbalance Nucleic Acid Biosensor Array Using Au Nanoparticle Signal Amplification

Sensors

Han Xia²  Feng Wang²  Qing Huang²  Junfu Huang²  Ming Chen²  Jue Wang²  Chunyan Yao²  Qinghai Chen²  Guoru Cai¹ 

[1] The 26th Research Institute, Chinese Electronic Scientific and Technical Group Company, Chongqing 400060, P.R China. E-Mail:;Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. E-Mails:

关键词: Au nanoparticle;    biosensor;    S. epidermidis;    quartz crystal microbalance;   

DOI  :  10.3390/s8106453

来源: mdpi

【 摘 要 】

Staphylococcus epidermidis is a critical pathogen of nosocomial blood infections, resulting in significant morbidity and mortality. A piezoelectric quartz crystal microbalance (QCM) nucleic acid biosensor array using Au nanoparticle signal amplification was developed to rapidly detect S. epidermidis in clinical samples. The synthesized thiolated probes specific targeting S. epidermidis 16S rRNA gene were immobilized on the surface of QCM nucleic acid biosensor arrays. Hybridization was induced by exposing the immobilized probes to the PCR amplified fragments of S. epidermidis, resulting in a mass change and a consequent frequency shift of the QCM biosensor. To further enhance frequency shift results from above described hybridizations, streptavidin coated Au nanoparticles were conjugated to the PCR amplified fragments. The results showed that the lowest detection limit of current QCM system was 1.3×10³ CFU/mL. A linear correlation was found when the concentration of S. epidermidis varied from 1.3×10³ to 1.3×10⁷ CFU/mL. In addition, 55 clinical samples were detected with both current QCM biosensor system and conventional clinical microbiological method, and the sensitivity and specificity of current QCM biosensor system were 97.14% and 100%, respectively. In conclusion, the current QCM system is a rapid, low-cost and sensitive method that can be used to identify infection of S. epidermidis in clinical samples.

【 授权许可】

CC BY   
© 2008 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.