A Surface Plasmon Resonance Sensor Platform Coupled with Gold Nanoparticle Probes for Unpurified Nucleic Acids Detection

Abstract

In this work, a surface plasmon resonance sensor system was designed and implemented for determination of nucleic acids in unpurified samples. First, through blocking non-specific interaction sites on the sensor surface to reduce non-specific adsorption from unpurified sample matrix, it was determined that at the optimal BSA concentration of 100 µg/ml the non-specific interaction can be reduced by 50%, although improvement for direct detection of nucleic acids in unpurified sample is required. Second, bearing nonspecific adsorption onto gold films, nucleic acids adsorbed on sensor surface in unpurified sample matrix were detected through a secondary hybridization approach. Using DNA-lined AuNPs shows the new SPR sensor can be applied for the determination of target ssDNA with a detection range of 0.1–10 µM for targets in purified and 1–10 µM in unpurified samples, respectively. Results imply that the new SPR sensor system is promising for specific and convenient analysis of nucleic acids directly in unpurified samples. Development of the new SPR sensor technique can have applications in fast field diagnostics and monitoring.

Keywords:

• DNA
• Gold nanoparticle
• Surface plasmon resonance
• Unpurified

Acknowledgments

This work was partially supported by the open research fund of state key laboratory of bioelectronics, Southeast University (Nanjing, China), National Basic Research Program of China (973 Program) (No. 2011CB707704), Advanced Space Medico-Engineering Research Project of China (No. SJ2010004), Key Project of the National Eleven-Five Year Research Program of China (2009BAK59B02), and the State Key Laboratory of Space Medicine Fundamentals and Application of China (SMFAII02).