Enhanced surface plasmon resonance for detection of DNA hybridization based on layer-by-layer assembly films

It was reported that the layer-by-layer (LBL) assembly films of (PAH/PSS) was used for the catalytic growth of Au nanoparticles (AuNPs) enhanced surface plasmon resonance (SPR). The results showed that not less than three layers of (PAH/PSS) modified on the Au surface could significantly reduce the background that comes from the metal deposition on Au surface in the process of the catalytic growth of AuNPs. With the low background achieved by the LBL assembly film of (PAH/PSS)3, sensitive detection of DNA hybridization using the catalytic growth of AuNPs enhanced SPR was demonstrated. Here, the detection limit of the catalytic growth of AuNPs enhanced SPR was 1.8 pM cDNA, which was five times lower than that of SPR enhanced by AuNPs only. Since such LBL assembly film was simple to prepare, the work described here provided an effective alternative for the construction of sensitive bioanalytical methods.