Design of molecularly imprinted sensor for detection of typhoid using immunoinformatics and molecular imprinting

Abstract

Typhoid disease caused by the bacterium Salmonella typhi becomes fatal if not treated timely. To expedite its timely and accurate diagnosis at an early stage, a biomimetic sensor based on epitope imprinting technique is developed for the detection of typhoid. Epitope sequence of Salmonella invasive protein D (SipD) was predicted using immunoinformatic tools and utilized for imprinting. A molecularly imprinted matrix was developed on the surface of quartz crystal microbalance chip through electropolymerization in presence of template - a 14-mer synthetic peptide predicted. Binding of ∼ −3000 Hz from the blood plasma sample of infected persons showed the selectivity of imprinted sites towards the SipD proteins of bacteria. The sensor was able to detect bacteria at an early stage with an LOD value of 0.50 (ng/ml). On extraction of the peptide sequence, imprinted cavities were able to selectively and specifically bind targeted epitope sequences in laboratory samples as well as ‘real’ samples of patients. An accurate, robust, cost-effective, facile diagnostic tool to aid the healthcare industry is presented here.

Keywords

• Typhoid
• Immunoinformatics
• Molecularly imprinted polymer
• Epitope
• Electroanalytical technique
• Diagnostic tool