Ω-Shaped Fiber-Optic Probe-Based Localized Surface Plasmon Resonance Biosensor for Real-Time Detection of Salmonella Typhimurium

Abstract

A novel, Ω-shaped fiber-optic localized surface plasmon resonance (FOLSPR) biosensor was designed for sensitive real-time and label-free bacterial detection. The designed Ω-shaped fiber-optic probe exhibits an outstanding sensitivity, due to the effect of unique geometry on performance. The results show that refractive index (RI) sensitivity of the Ω-shaped fiber-optic probe is 14 times and 2.5 times higher than those of the straight-shaped and the Ushaped FOLSPR, respectively. In addition, the reason for the geometry and the bending radius effects on RI sensitivity was discussed by investigating the relationship between RI sensitivity and the bending area. The results show that RI sensitivity was enhanced with the increase of bending area, and the best RI sensitivity obtained by Ω-shaped FOLSPR was 64.582 (a.u.)/RIU. Combined with this newly designed Ω-shaped FOLSPR biosensor, a real-time, label-free, sensitive, and highly selective bacterial detection method was established. In this work, the aptamers immobilized on the surface of FOLSPR could specifically capture Salmonella Typhimurium, resulting in an intense change of the absorption peak. In line with this principle, the FOLSPR biosensor achieved high detection sensitivity for Salmonella Typhimurium down to 128 CFU/mL within a linear range from 5 × 10 2 to 1 × 10 8 CFU/mL and showed good selectivity for Salmonella Typhimurium detection compared to other bacteria. Furthermore, the FOLSPR biosensor was successfully applied to the detection of Salmonella Typhimurium in a chicken sample with the recoveries of 85−123%. With these characteristics, the novel biosensor is a potential alternative tool in food analysis and environmental monitoring.

Recent Advances in the Detection of Antibiotic and Multi-Drug Resistant Salmonella: An Update

“…In 2018, a Ω-Shaped Fiber-Optic Probe-Based Localized Surface Plasmon Resonance (FOLSPR) Biosensor was used in the quantification of S. Typhimurium. The sensor detected S. Typhimurium down to 128 CFU/mL within a linear range from 5 × 10 2 to 1 × 10 8 CFU/mL [89].…”

An enzyme-mediated universal fluorescent biosensor template for pathogen detection based on a three-dimensional DNA walker and catalyzed hairpin assembly

“…In order to prevent the spread of infectious diseases, developing a sensitive and accurate analytical method for pathogen detection is of great significance to food safety and global public health. [3][4][5][6] In the past, a large number of pathogen analysis methods, such as the culture and colony counting method, the polymerase chain reaction (PCR) and the enzyme-linked immunosorbent assay (ELISA) have been developed. [7][8][9] However, these traditional methods are costly and labor-intensive and require specialized instruments and operators, which are difficult to meet the requirement of bioanalysis nowadays.…”

Self-extending DNA-Mediated Isothermal Amplification System and Its Biosensing Applications

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