Bacterial Nanocellulose Membrane Deposited with Silver Nanoparticles for SERS Detection of Microplastics

Due to its high sensitivity and good reproducibility, surface-enhanced Raman scattering (SERS) is widely used in various fields. The rigidity and brittleness of traditional rigid substrates limit their application in specific fields. Herein, a flexible SERS substrate is developed by depositing well-dispersed silver nanoparticles (AgNPs), synthesized via an improved citrate reduction method, onto bacterial nanocellulose (BNC) membranes. The substrate leverages the electromagnetic enhancement properties of AgNPs and the compact structure of BNC, achieving a significant Raman signal enhancement for polyethylene solutions at a concentration of 0.1 g/L with an enhancement factor of up to 331.49. Meanwhile, it demonstrates excellent uniformity, reproducibility, and stability, maintaining robust SERS performance even in complex aqueous environments, such as tap water and lake water. Furthermore, the fabrication process is simple, rapid, and cost-effective, making it suitable for the on-site detection of microplastics. Systematic characterization and real-world water sample testing confirmed the substrate’s high sensitivity and applicability for environmental pollutant detection, offering a promising approach for flexible SERS-based sensing platforms.