Fabrication of an Ag-based SERS nanotag for histamine quantitative detection

A crucial issue in analytical science and physiology is the detection of histamine with high sensitivity, specificity and credibility, which served as an important neurotransmitter in biofluids. Despite the high sensitivity of surface-enhanced Raman spectroscopy (SERS) at the level of single molecule, there are still challenges in providing high sensitivity for histamine with a small cross section. For the selective detection of histamine using SERS, a highly sensitive sandwich structure substrate combining Fe₃O₄ and an Ag-based SERS nanotag was developed. The Fe₃O₄@SiO₂-COOH served as a capture component for enriching histamine. Upon functionalized Ag nanoparticles with glycine (Gly) and (3-Aminopheyonyl) boronic acid (APBA), they were then used to connect with histamine and serve as a SERS nanotag, respectively. A linear relationship between the Raman intensity and the histamine concentration was observed over the range 10^-4-10^-8 M with a limit of detection of 7.24 × 10^-9 M. This methodology also exhibited good selectivity in the presence of other neurotransmitters. With our new approach, histamine can be detected sensitively and reliably in fish samples, which indicates the potential prospect of an effective method for analyzing histamine in complex specimens.