Synthesis of silver nanoparticles on polyacrylonitrile nonwoven substrates with the silver mirror reaction for effective SERS detection of 4-MBA and glucose†

We present a simple, fast, and efficient method for the production of silver nanoparticles (AgNP) for surface-enhanced Raman spectroscopy (SERS) applications. The method utilizes the classical silver mirror reaction, with ascorbic acid serving as the reducing agent, to produce AgNP on polyacrylonitrile non-woven substrates. Different protocols were used to functionalize the substrates with AgNP in situ. Optimization of the substrate modification procedure led to SERS-substrates with an enhancement factor (EF) of up to 10⁶ (4-MBA detection) for samples treated with 1 M solutions of AgNO₃ and NH₃·H₂O. The obtained substrates were further modified with glucose oxidase (GOx), and glucose sensing was carried out in a concentration range from 0.5 mM to 10 mM. Machine learning models, such as random forest and gradient boosting, were used for the analysis of Raman data. The resulting substrates have potential applications in various fields of analytical chemistry.