Two dimensional photonic crystal biosensors as a platform for label- free sensing of biomolecules

摘要

Resonant optical microcavites of two-dimensional photonic crystals (2D PhC) are responsive to refractive index changes in the immediate vicinity and thus provide a label-free platform for sensing biological molecules. Because their active sensing volume is ～1 μm~3, exceptionally sensitive detection of biomolecules is, in principle, achievable from complex biological samples. Previously, we have demonstrated detection of human-IgG protein and virus-like particles by measuring changes in the optical transmission spectrum from the 2D PhC after it has been treated with analyte and dried. However, this drying step restricts practical utility of the platform especially in the case of clinical diagnostics wherein multiple samples need to be tested in short duration. In our progress toward this, we have demonstrated successful integration of microfluidic channels with the 2D PhC device and we further characterized the temperature and bulk refractive index sensitivity of the device.