46 / 2025-03-31 21:56:44

Polyethersulfone-Derived Laser-Induced Porous Graphene-Based Biosensor for Point-of-Care Detection of Salmonella

Laser-induced graphene, electrochemical sensing, polyethersulfone membrane, immunomagnetic beads, label-free biosensor, Salmonella typhimurium detection.

3. 智慧牧场与动物福利 > （3）智慧养殖的传感器、智能感知和机器人

Animal disease is one of the top threatens for poultry and livestock breeding, and diagnosis of animal disease through the detection of bacteria is essential. Foodborne pathogenic bacteria cause significant fatalities, highlighting the need for rapid and sensitive on-site detection. Current methods are reliable but impractical for field use, leading to a focus on developing point-of-care devices. This study introduces a polyethersulfone-laser-induced graphene (PES-LIG) composite electrode for sensitive electrochemical detection of Salmonella typhimurium (St.). The LIG electrode was made by laser scribing a porous PES membrane, creating a conductive graphene layer that combines filtration with enhanced electrochemical activity. The PES-LIG electrode demonstrated a 1.4-fold increase in electrochemically active surface area compared to its geometric area, driven by high surface roughness and conductivity. Electrochemical characterization revealed exceptional stability (1.4% peak current variation) and diffusion-controlled redox behavior. For St. detection, immunomagnetic beads (IMBs) captured target bacteria, which were filtered onto the electrode surface, impeding charge transfer and increasing charge-transfer resistance (Rct). The sensor achieved a LDR of 1 × 10² - 1 × 10⁶ CFU mL^-1 and a low LOD (32 CFU mL^-1), surpassing many existing methods. Specificity testing against E. coli, L. monocytogenes, and V. parahaemolyticus (10⁶ CFU mL^-1) confirmed high selectivity due to antibody-functionalized IMBs. The electrode’s integrated filtration-electrochemical sensing design enables rapid detection (4 minutes) without complex instrumentation or labeling. This work establishes a robust, cost-effective platform for foodborne pathogen analysis and clinical diagnostics, underscoring the potential of LIG-based composites in advancing biosensing technologies for public health and safety.