<p>Flavin mononucleotide (FMN) plays an important role in living systems. Accurate probing and characterizing of FMN is the key to understanding the contribution of FMN coenzyme in biological processes. We demonstrate a way to get a bright surface-enhanced Raman spectroscopy (SERS) signal while simultaneously quenching the fluorescence background through silver nanorod (AgNR) array substrates fabricated by the oblique angle deposition method. The AgNR array substrates show a good SERS activity with an enhancement factor of ∼4.2 × 10<sup>4</sup>. Meanwhile, the characteristic peaks of FMN are assigned by the density function theory calculation. An exponential relationship is demonstrated between SERS intensity and FMN concentration in the concentration range of 0.1 to 100 mg / L. This SERS-based method enabled the rapid and highly sensitive detection of FMN, holding great promise for expanding SERS application in biochemistry and food safety fields.</p>
Acesulfame potassium (AK) is widely used in the food industry. However, it does harm to the liver and nervous system. Here, a rapid method based on surface-enhanced Raman spectroscopy (SERS) was developed for the detection of AK in mouthwash. As the results show that the characteristic peaks of AK were at 549, 641, and 1650 cm − 1. The vibrational modes of each peak were calculated by density functional theory. This method can detect AK in mouthwash samples within 3 min without any complicated pretreatment. These results suggested that this SERS-based method for rapid determination of AK in mouthwash was sensitive and reliable. It is expected that this method possesses great potential in monitoring the quality of mouthwash.