Localized Surface Plasmon Resonance Optical Biosensor for Simple Detection of Deoxyribonucleic Acid Mismatches

Optical biosensors are optical technologies that evaluate changes in the refractive index as they monitor non-covalent molecular interactions in real time. These make use of unsophisticated, label-free analytical approaches, which do not require dyes to produce a visible signal. In this study, the efficiency of localized surface plasmon resonance (LSPR) biosensor in detecting a single nucleotide mismatch in deoxyribonucleic acid is examined. The detection is based on the hybridization of a target DNA at 100 ng μL⁻¹ with a complementary biotinylated probe as well as a partially complementary biotinylated with one nucleotide mismatch probe on a gold-coated surface. Both probes are used at a concentration of 0.1 μm. The LSPR exhibited sensitivity by differentiating sample M+ from sample C+ through varying transmission intensities of 0.28 and 0.26 μA, respectively. Based on these findings, this approach demonstrates a great potential due to its ability to distinguish samples that differ with a single base pair, and its efficiency will be explored in the development of a point-of-care device as a simpler and cost-effective approach for detection of various biologically and medically significant mutations such as antimicrobial resistance mutations. More work is underway to determine the robustness of the LSPR biosensor using the biotin–neutravidin approach.