Rapid detection of Salmonella using an aptamer-functionalized PDA liposome sensor with naked-eye colorimetric sensing

Abstract

The increasing occurrence of Salmonella pathogens responsible for foodborne diseases is of mounting global concern within the sphere of public health and consumer welfare. Detecting Salmonella holds pivotal importance in averting these illnesses. The complex pretreatment process, time-consuming nature, and expensive equipment associated with existing detection methods have posed barriers to the development of sensors capable of rapidly and effortlessly detecting pathogens in real-life scenarios. Therefore, the development of a colorimetric sensor capable of rapid and facile pathogen detection, without the need for complex sample preparation or expensive detection equipment, is a crucial research direction for ensuring food safety. In this study, we successfully engineered a PDA-based liposome sensor decorated with an aptamer that specifically interacts with Salmonella typhimurium, enabling the rapid and accurate detection of Salmonella via a colorimetric response. This aptamer-functionalized PDA sensor exhibited a distinct color change (colorimetric response of 15.7% for 1 × 10⁴ CFU mL⁻¹Salmonella) within 15 minutes, accompanied by a highly linear increase in the CR values as the Salmonella concentration increased. In addition, the developed sensor materials can also effectively detect Salmonella in real food through a colorimetric reaction. We developed a colorimetric biosensor capable of detecting foodborne pathogens like Salmonella, with the naked eye in a simple and fast way, which demonstrates promising potential for sensor materials that could be extensively utilized in practical applications.