DNA induced CTAB-caped gold bipyramidal nanoparticles self-assembly using for Raman detection of DNA molecules

DNA is an indispensable part of metabolism, which affects many important processes in the body, including gene expression, protein synthesis, and drug delivery. Surface-enhanced Raman spectroscopy (SERS) is one of the most important methods used to study the structure and function of DNA and can obtain rich DNA molecular fingerprints. However, it is still a great challenge to use SERS to directly analyze the characteristic Raman signals of the DNA molecule and achieve rapid and simple detection. Hence, a detection platform based on gold bipyramidal nanoparticles (AuNBs) self-assembly that can be directly used for the detection of DNA molecules without the need for additional aggregators and cleaning agents was designed in this study. The original hexadecyltrimethylammonium bromide (CTAB) of AuNBs can be used as the internal standard for DNA quantification without an additional standard. This is the first time that the Raman signals of the analyte molecule can be obtained directly without labels by using the interaction between the molecule and the enhanced substrate. We used this method to capture the original DNA molecules in methylated DNA, serum, and cell metabolites and obtained spectral data processing results using linear discriminant analysis (LDA). This provides new ideas for the digitization of disease treatment and the study of the metabolic processes of life.