A cyclable detection of histamine by using the DNA microfluidic chip with high SERS performance

This study reports a SERS-based microfluidic chip for the cyclic detection of histamine with high specificity. Easily fabricated Au nanoparticles (AuNPs) were synthesized on Si substrates by using a thermally treating approach. The designed probe DNA (pDNA) functionalized AuNPs is used as a sensing surface. The Cyanine 3 (Cy3) functionalized complementary DNA (cDNA) is modified on the chemically synthesized AuNPs and the complex cDNA/AuNPs are used as nanotags. Due to the hybridization between the pDNA and the cDNA, nanotags-pDNA/AuNPs structure is formed and illustrates a high SERS intensity of Cy3. With the presence of the histamine, due to the stronger affinity between cDNA and histamine, nanotags-pDNA/AuNPs structure is destroyed and the nanotags are separated from the sensing surface resulting in a decrease in the SERS intensity of Cy3. By adding fresh nanotags, nanotags-pDNA/AuNPs structure is regenerated, and a new detection cycle can be performed. By utilizing the proposed SERS-based microfluidic chip, the limit of detection (LOD) of histamine in DI water is 1 × 10 −9  g/mL. The concentration is well below the U.S. Food and Drug Administration (FDA) histamine toxicity threshold of 5 × 10 −5  g/mL. Moreover, the proposed SERS-based microfluidic chip can be reused 7 times. Furthermore, this chip has accuracy and applicability were validated through its application in beer samples. Indicating that this method has great potential for histamine detection.