DGTD modelling of Mie scattering phenomenon of gold nano particles of bio sensing applications

摘要

Personal wearable medical devices and sensors have become more popular which results in better resources optimization and a better systematic monitoring or health condition. The ability to extract quantitative information in living cells without actual biopsy (disturbance in the structure of the cell) can be used to study and monitor morphological and physiological changes such as pre-cancerous or cancerous conditions. Basically, light scattered from a cell depends on the size of the cell, structure of the cell and the properties of the incident light. It is also termed as "optical biopsy". Such Mie scattering based Lab-on-a-Chip (LOC) sensor device if implemented can be used for early diagnosis of terminal diseases such as cancer. Gold nano particle acts as a sensor on this wearable device. Mie scattering based nonlinear optical phenomenon is used for cancer detection. This work involves modelling, simulation and analysis of a nano sensor using Discontinuous Gallerkin Time Domain method (DGTD). Light is used from arbitrary shaped objects at various incident angles. The Mie solution to Maxwell's equations describes the scattering of an electromagnetic plane wave by a homogeneous sphere. Mie scattering theory has been used to determine whether scattered light from tissue corresponds to healthy or cancerous cell nuclei using angle resolved low coherence interferometry. Gold nanoparticle has been used in biological applications and it is necessary to know the co-efficient of scattering and co-efficient of absorption. Mie scattering has no upper limits with respect to size of the particle.