Environmental Stability of Plasmonic Biosensors Based on Natural versus Artificial Antibody

Plasmonic biosensors based on the refractive index sensitivity of localized surface plasmon resonance (LSPR) are considered to be highly promising for on-chip and point-of-care biodiagnostics. However, most of the current plasmonic biosensors employ natural antibodies as biorecognition elements, which can easily lose their biorecognition ability upon exposure to environmental stressors (e.g., temperature and humidity). Plasmonic biosensors relying on molecular imprints as recognition elements (artificial antibodies) are hypothesized to be an attractive alternative for applications in resource-limited settings due to their excellent thermal, chemical, and environmental stability. In this work, we provide a comprehensive comparison of the stability of plasmonic biosensors based on natural and artificial antibodies. Although the natural antibody-based plasmonic biosensors exhibit superior sensitivity, their stability (temporal, thermal, and chemical) was found to be vastly inferior to those based on artificial antibodies. Our results convincingly demonstrate that these novel classes of artificial antibody-based plasmonic biosensors are highly attractive for point-of-care and resource-limited conditions where tight control over transport, storage, and handling conditions is not possible.