Noble Metal-Enhanced Chemically Sensitized Bi2WO6 for Point-of-Care Detection of Listeria monocytogenes in Ready-to-Eat Foods

TL;DR

This paper introduces a new sensor using a special nanomaterial to detect Listeria monocytogenes in ready-to-eat foods quickly and without damaging the sample.

Contribution

The novel contribution is the development of a high-performance Au-Bi2WO6 composite nanomaterial for rapid and non-destructive pathogen detection.

Findings

The Au-Bi2WO6 composite showed high sensitivity (Ra/Rg = 36.9@50 ppm) and fast response–recovery kinetics (13/12 s) for acetoin detection.

Efficient electron exchange between Au and Bi2WO6 was confirmed, enhancing the sensor's performance.

The sensor outperforms conventional turbidimetry for detecting foodborne pathogens.

Abstract

Listeria monocytogenes (LM) contamination constitutes a paramount global threat to food safety, necessitating the urgent development of advanced, rapid, and non-destructive detection methodologies to ensure food security. This study successfully synthesized Bi2WO6 nanoflowers through optimized feed ratios of raw materials and further functionalized them with noble metal Au to construct a high-performance Au-Bi2WO6 composite nanomaterial. The composite exhibited high sensing performance toward acetoin, including high sensitivity (Ra/Rg = 36.9@50 ppm), rapid response–recovery kinetics (13/12 s), and excellent selectivity. Through UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and X-ray photoelectron spectroscopy (XPS) characterizations, efficient electron exchange between Au and Bi2WO6 was confirmed. This electron exchange increased the initial resistance of the material, effectively enhancing the response value toward the target gas. Furthermore, the chemical sensitization effect of Au significantly increased the surface-active oxygen content, promoted gas–solid interfacial reactions, and improved the adsorption capacity for target gases. Compared to conventional turbidimetry, the Au-Bi2WO6 nanoflower-based gas sensor demonstrates superior practical potential, offering a novel technological approach for non-destructive and rapid detection of foodborne pathogens.

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