Determination of Salmonella Typhimurium by Fourier Transform Infrared (FTIR) Spectroscopy Using a Hydrogenated Amorphous Silicon Carbide (a-SiC:H) Thin Film

Abstract

Salmonella is one of the main microorganisms that causes food-borne illnesses worldwide, although there are standard procedures to determine its presence or absence in food samples. However, these methodologies are time consuming and cumbersome, so the development of devices that rapidly and accurately determine bacteria is necessary. Various materials have been used to construct these devices. Hydrogenated amorphous silicon carbide (a-SiC:H) is one of the least studied. Therefore, in the present work, self-assembled monolayers were applied on a-SiC:H thin films to determine Salmonella Typhimurium ATCC 14028 by Fourier transform infrared spectroscopy. The detection of this microorganism was performed between 1060 and 960 cm⁻¹ corresponding to carbohydrate and phosphate groups of the bacteria. The lowest detected concentration was 10 CFU/mL. This work confirms the utility of a-SiC:H to reliably and rapidly determine Salmonella.

Keywords:

• Fourier transform infrared (FTIR) spectroscopy
• hydrogenated amorphous silicon carbide (a-SiC:H)
• immunosensor
• Salmonella
• self-assembled monolayers (SAM)
• thin films

Additional information

Funding

The authors thank Consejo Nacional de Ciencia y Tecnología (CONACYT) for the financial support by basic science project number 256513 and the scholarship granted to the first author to study Doctorate in Biotechnology Sciences within the Doctorate Program of the Instituto Politécnico Nacional included in the list of Postgraduate Degrees of Excellence.