Graphene isolated Au nanoparticle arrays with high reproducibility for high-performance surface-enhanced Raman scattering

An efficient surface enhanced Raman scattering (SERS) substrate has been developed based on highly ordered arrays of graphene–isolated Au nanoparticle (G/AuNP). By combining the electromagnetic enhancement activity of AuNP arrays and unique physical/chemical properties of graphene, the G/AuNP arrays shows high performance in terms of sensitivity, signal-to-noise ratio and reproducibility. The average enhancement factor obtained from the G/AuNP arrays for rhodamine 6G probe molecules is over 10 7 . The maximum deviations of SERS intensities from 20 positions of a same SERS substrate are in the range of 4.74% to 6.89% and from 20 different substrates in various batches are in the range of 5.67% to 8.37%, depending on different vibration modes. As a practical application of this SERS system, we detect the adenosine concentration in human serum. The detection results show a good linear correlation between SERS intensity and adenosine concentration within the range of 2 to 250 nM. This work may open up new opportunities in developing the applications of SERS in biomedical diagnostics, biological sensing and other biotechnology.