Target triggered self-assembly of Au nanoparticles for amplified detection of Bacillus thuringiensis transgenic sequence using SERS

• Published in: Biosensors & bioelectronics 2014-12, Vol.62, p.196-200
• Main Authors: Chen, Kun, Wu, Long, Jiang, Xiaochun, Lu, Zhicheng, Han, Heyou
• Format: Article
• Language: English
• Subjects: Amplification; Au nanoparticles; Bacillus thuringiensis; Bacillus thuringiensis - genetics; Bacillus thuringiensis transgene; Base Pair Mismatch; Biological and medical sciences; Biosensing Techniques - methods; Biosensors; Biotechnology; Deoxyribonucleic acid; DNA biosensors; DNA, Bacterial - genetics; DNA, Recombinant - genetics; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Gold; Hybridization chain reactions; Metal Nanoparticles; Methods. Procedures. Technologies; Nanotechnology; Nanowires; Platforms; Raman scattering; Real-Time Polymerase Chain Reaction; Self assembly; Spectrum Analysis, Raman - methods; Surface enhanced Raman scattering; Transgenic; Various methods and equipments
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.06.046

The research methods for DNA detection have been widely extended since the application of nanotechnology, but it remains a challenge to detect specific DNA sequences or low abundance genes in the biological samples with accuracy and sensitivity. Here we developed a SERS biosensing platform by target DNA (tDNA) triggered self-assembly of Au nanoparticles (Au NPs) probes on DNA nanowires for signal amplification in DNA analysis. Based on the hybridization chain reactions (HCR) and surface enhanced Raman scattering (SERS) technology, the SERS intensity reveals a good linearity with tDNA ranging from 50pM to 500pM under optimal conditions. The specific detection of tDNA sequence was realized with a detection limit of 50pM (S/N=3). To demonstrate the specificity and universality of the strategy, the single-base mismatches in DNA and the Bacillus thuringiensis (Bt) transgenic sequence were successively applied in the SERS assay. The results showed that the sensitivity and accuracy of the SERS-based assay were comparable with real-time PCR. Besides, the method would provide precise and ultra-sensitive detection of tDNA but also informative supplement to the SERS biosensing platform. •A universal SERS sensing platform was developed for sensitive detection of DNA.•DNA–Au NPs amplification units were adopted to obtain high sensitivity.•The method required fewer steps and lower experimental requirements.•The biosensors strategy could be extended to electrochemical detection for DNA.