Ren Hai-Cang, Vollmer Frank, Arnold Stephen, Libchaber Albert
Opt Express. 2007 Dec 10;15(25):17410-23. doi: 10.1364/oe.15.017410.
Theory is developed for frequency shift and linewidth-broadening induced by rodlike bacteria bound to micro-optical resonators. Optical shift of whispering gallery modes (WGMs) is modeled by introducing a form factor that accounts for random horizontal orientation of cylindrical bacteria bound by their high refractive index cell walls. Linewidth-broadening is estimated from scattering losses. Analytic results are confirmed by measurement using E.Coli as model system (~10(2) bacteria/mm(2) sensitivity), establishing the WGM biosensor as sensitive technique for detection and analysis of micro-organisms.
本文提出了一种理论，用于研究附着在微光学谐振器上的杆状细菌引起的频率偏移和线宽展宽。通过引入一个形状因子来模拟回音壁模式（WGM）的光学偏移，该形状因子考虑了由高折射率细胞壁束缚的圆柱形细菌的随机水平取向。线宽展宽是根据散射损耗估算的。以大肠杆菌为模型系统进行的测量（灵敏度约为10(2)个细菌/平方毫米）证实了分析结果，确立了WGM生物传感器作为检测和分析微生物的灵敏技术。
