Toll-Like Receptor-4 immobilized carboxylic terminated carbon interfaces towards a cost-effective and label-free detection of gram -ve bacteria.

Bacterial biofilms in chronic wounds are primarily responsible for delayed wound healing and affect a person’s life quality. A patient’s recovery depends on the treatment based on the speedy diagnosis of the wound or bacteria responsible for biofilm formation. Identification plays an essential role in the best recovery of a patient, and electrochemical techniques are best suited. In this work, we utilized the cost-effective and in-house developed carboxylic-terminated carbon paste electrode’s surface immobilized with TLR-4 to identify gram-ve bacteria, i.e., E.coli. A miniaturized electrochemical cell was used to accommodate these electrodes, which also helped in reducing sample wastage and improving the detection limit. The fabricated electrodes detected E.coli with a very low detection limit of 0.13 CFU/mL. When tested with nonspecific bacteria and fungi, the proposed platform demonstrated excellent specificity and selectivity towards gram -ve bacteria and the mixture of both gram +ve/-ve bacteria and fungi. The bioelectrodes stored for more than two weeks were tested on various days, and the results indicated an excellent shelf-life for the proposed platform.