Phenformin hydrochloride (PHE), once used as a traditional anti-diabetic drug, has now been banned due to significant side effects. However, the phenomenon of the illegal addition of PHE to hypoglycemic healthcare products is still rampant. Thus, the detection of illegally added PHE is urgently needed. Surface-enhanced Raman scattering (SERS) is a promising candidate for this purpose, but the weak affinity between PHE and bare metal (Au or Ag) limits direct SERS detection of PHE. In this paper, we prepared Ag nanoparticles coated with β-cyclodextrin (AgNP@β-CD), which display the coffee-ring effect, that can be used for PHE sensing. β-CD-functionalized nanoparticles could capture the analyte and fix the molecular orientation in the hydrophobic cavity. The coffee-ring effect could improve the SERS effect through a higher concentration of the analyte, higher density of nanoparticles, and more hot spots. The SERS performance of the AgNP@β-CD substrate was characterized by using o-phenylenediamine dihydrochloride as a probe molecule. The excitation wavelength and pH value were optimized. A linear response for PHE detection is in the 7.0 × 10⁻⁸–1.0 × 10⁻⁶ mol L⁻¹ concentration range, and the limit of detection is as low as 8.0 × 10⁻⁹ mol L⁻¹. This AgNP@β-CD coffee-ring effect substrate was applied to the detection of PHE in healthcare products, with recoveries between 95.3 and 105.0% and relative standard deviations of less than 5.16%. It is anticipated that the AgNP@β-CD substrate will also have great potential for the monitoring of other aromatic drugs in healthcare products.

曾经用作传统抗糖尿病药物的盐酸苯乙双胍（PHE）由于明显的副作用而被禁止使用。然而，在低血糖保健产品中非法添加PHE的现象仍然很普遍。因此，迫切需要检测非法添加的PHE。表面增强拉曼散射（SERS）是实现此目的的有希望的候选方法，但是PHE与裸金属（Au或Ag）之间的弱亲和力限制了SHE对PHE的直接检测。在本文中，我们制备了涂有β-环糊精（AgNP @β-CD）的Ag纳米颗粒，该纳米颗粒具有咖啡环效应，可用于PHE传感。β-CD-官能化的纳米颗粒可以捕获分析物并固定疏水腔中的分子方向。咖啡环效应可以通过更高的分析物浓度，更高的纳米颗粒密度和更多的热点来改善SERS效应。通过使用邻苯二胺二盐酸盐作为探针分子表征AgNP @β-CD底物的SERS性能。优化了激发波长和pH值。PHE检测的线性响应为7.0×10^-8 –1.0×10 ^-6  mol L ^-1的浓度范围，检测限低至8.0×10 ^-9  mol L ^-1。该AgNP @β-CD咖啡环效应底物用于检测保健产品中的PHE，回收率在95.3％至105.0％之间，相对标准偏差小于5.16％。可以预料，AgNP @β-CD底物还将具有监测医疗保健产品中其他芳香药物的巨大潜力。