In this study, we developed a simple and sensitive surface-enhanced Raman scattering (SERS) technique for the detection of choline in infant formulas based on a filter-based flexible substrate. The flexible substrate with excellent SERS activity and reproducibility was fabricated using a syringe filter and Ag triangular nanoplates. The Raman marker, 3-mercaptophenylboronic acid, was oxidised to 3-hydroxythiophenol in the presence of H₂O₂, which caused a decrease in the SERS peak intensity ratio (I_1021 cm^-1: I_996 cm^-1). Utilising the enhanced flexible substrate, a quantitative detection method for H₂O₂ was developed. Additionally, choline could be hydrolysed by choline oxidase to generate betaine and H₂O₂. Thus, the SERS method was successfully applied to detect choline in the concentration range of 10^-3–10^-7 M with a beneficial limit of detection as low as 8.36 nM. Importantly, the recovery of choline from infant formula milk powder was approximately 99%. The excellent performance of the flexible substrate-based SERS method demonstrated its potential for application in H₂O₂-generated oxidase-based biosensing.

在这项研究中，我们开发了一种简单且灵敏的表面增强拉曼散射（SERS）技术，用于基于基于过滤器的柔性基材检测婴儿配方食品中的胆碱。使用注射器过滤器和Ag三角纳米板制造了具有出色SERS活性和可重复性的柔性基板。在H ₂ O ₂存在下，拉曼标记3-巯基苯基硼酸被氧化为3-羟基苯硫酚，这导致SERS峰强度比（I _{1021 cm} ^-1：I _{996 cm} ^-1）降低。利用增强的柔性基板，H ₂ O ₂的定量检测方法发展了。另外，胆碱可以被胆碱氧化酶水解以产生甜菜碱和H ₂ O ₂。因此，SERS方法成功地用于检测浓度范围为10 ^-3 –10 ^-7 M的胆碱，检测限低至8.36 nM。重要的是，婴儿配方奶粉中胆碱的回收率约为99％。基于柔性底物的SERS方法的出色性能证明了其在H ₂ O ₂生成的基于氧化酶的生物传感中的应用潜力。