Development of Zinc Oxide Thin-Film Biosensors for Salmonella Detection
Resumen
In this study, titled “Development of Zinc Oxide Thin-Film Biosensors for Salmonella Detection,” two different biosensor assembly methods were evaluated to determine their effectiveness in immobilizing IgG antibodies for the detection of Salmonella at varying concentrations (UFC/mL). The first method, referred to as immersion, involved sequential submersion of Corning glass substrates during each assembly step. The second method, drip-coating, consisted of localized deposition of reagents onto the substrate surface. The drip method allowed for targeted signal detection in a defined sensor area, achieving a stronger response in less time.
Both approaches were analyzed using FTIR spectroscopy (400–4000 cm?¹), with the primary detection band observed between 1000–1100 cm?¹, particularly at 1050 cm?¹, corresponding to interactions with the lipopolysaccharide (LPS) components of the Salmonella cell wall. Additionally, reductions in the amide I and II bands indicated successful antigen-antibody binding.
The biosensor demonstrated a detection limit of 100 UFC/mL within a total assay time of 15 minutes, including 10 minutes of antigen incubation and 5 minutes of air drying. These findings support the potential of ZnO thin-film biosensors as rapid, sensitive tools for pathogen detection in real-time applications.