Dual template (epitope) imprinting of Mycobacterium leprae bacterial protein for enhanced MIP-EQCM sensing

Leprosy, often known as Hansen's disease, is a chronic bacterial infection caused by Mycobacterium leprae (M. leprae) bacteria. The bacterium has a long incubation period, making it challenging for diagnosis. Timely diagnosis is crucial in initiating early treatment and preventing disease progression and complications. Herein, we proposed a dual-epitope imprinted polymer sensor for M. leprae bacterial protein. Two peptide (epitope) sequences unique to the bacteria were selected and immobilized onto gold nanoparticles, followed by polymerization using multiple monomers 2-methacryloyloxyethyl phosphorylcholine (2-MPC), benzyl methacrylate (BM), and 4-aminothiophenol (4-ATP), selected through in silico molecular docking strategy and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. The imprinted polymer was electrodeposited on the gold coated electrochemical quartz crystal microbalance (EQCM) electrode. The sensor was able to show specific binding towards the real blood samples of leprosy patients. The limit of detection (1.39-1.82 nM) and limit of quantification (4.20-5.51 nM) with no cross reactivity and matrix effect indicate high sensitivity and selectivity. The sensor exhibits a significant improvement in selectivity and adsorption capacity over conventional sensors, with add-on advantages of reusability, high selectivity and sensitivity.