A central composite face-centered design for optimizing the detection of Salmonella typhi with a fluorescence nanobiosensor using the microcontact method

The rapid detection of Salmonella typhi can be accomplished by developing nanobiosensor kits. Accordingly, in the present study, a molecularly imprinted polymer (MIP) was developed, formed via covalent bonds among methacrylic acid (MAA) monomers and hydrogen bonds between MAA and antibodies. Using this MIP, S. typhi antigen was detected with a fluorescence converter. The S. typhi concentration could be determined at 10 colony/mL (minimum) in polluted water. A spectrofluorometer was used to quantify the findings. In addition, Escherichia coli was inseminated in an aqueous environment containing S. typhi, and no interference with the sensor function was found. The sensor sensitivity was measured for 60 days, and the sensor performance was verified for 56 days. Thereafter, the performance diminished. The present findings indicated the sensitive and precise role of the sensor in detecting S. typhi antigens at concentrations of 10⁻¹–10⁹.