Computational designing and synthesis of epitope imprinted sensor with zwitterionic polymeric matrix for sensitive, specific and selective sensing of protein

Abstract

Lactoferrin (Lf) protein is a member of the transferrin family, present in mature milk, transitional milk, and colostrum milk. It has antibacterial, antiviral, immunomodulatory, anticancer, and prebiotic properties, and vital in many biomedical and biotechnological applications, and also serve as biomarker for several disorders, viz. Alzheimer's disease, inflammatory bowel disease, subclinical mastitis, dry eye disease, etc. Here, N-terminal region peptide of Lf is chosen for epitope imprinting. This epitope sequence was imprinted on electrochemical quartz crystal microbalance (EQCM) electrode using multiple monomer approach. The monomers were chosen through in silico molecular docking for to select appropriate set of monomers for chosen peptide sequence as target analyte. A zwitterionic monomer 2-methacryloyloxyethyl phosphorylcholine (MPC) with benzyl methacrylate (BMA) and 4-aminothiophenol (4-ATP) were predicted for crafting imprinted polymer matrix. On extraction of the peptide (epitope) sequences, imprinted cavities were capable to selectively and specifically capture intended peptide (epitope) sequences in laboratory samples as well as ‘real’ samples. Selectivity of sensor was examined through mismatched peptide sequences and certain plasma proteins also. The sensor was able to show specific binding towards the ‘real’ samples of milk, even in the presence of ‘matrix’ and other proteins. The limit of detection and quantification was found to be 5.25 nM and 17.51 nM respectively with imprinting factor as 10.91. Good analytical performance was shown by the devised technique, high sensitivity and selectivity with no matrix interference. © 2025 Elsevier B.V.