表面单层组装多环芳烃荧光行为的Monte Carlo模拟

Fluorescence Behavior of Aromatic Compounds Immobilized on A Substrate Surface: A Monte Carlo Simulation

用MonteCarlo方法模拟了惰性基片表面单层组装多环芳烃 (传感元素 )的荧光行为 ,考察了基片表面传感元素固定化百分率、传感元素激发百分率 (光吸收效率 )以及传感元素分子在介质中相互缔合形成激基缔合物趋势大小 (用P表示 ,P值介于 0到 1)等因素对传感元素激基缔合物荧光发射强度与单体荧光发射强度之比所产生的影响 .结果表明 ,具有中等光吸收效率的多环芳烃适宜于作为传感元素 。

Recently, a series of sensing films based upon the s upra-molecular behavior of aromatic compounds immobilized on substrate surfaces and its dependence to the composition of the medium have been successfully prep ared. It is found that the properties and performances of the films depend upon various factors, including the nature of the sensing element, the way of immobil ization, the nature of the substrate, and the density of the sensing element imm obilized etc. To accelerate and deepen the studies, it was decided to carry out the theoretical simulation of the sensing films based upon the proposed principl e. The fluorescence behavior of a functional plate, of which the surface is func tionalized by single layer immobilization of aromatic compounds (sensing element s), is simulated by Monte Carlo simulation method. The effects of the immobiliza tion density of a sensing element, the excitation efficiency, and the associatio n efficiency, P, which is a characteristic parameter of an aromatic compound , between the molecules of the sensing element on the ratio of the excimer emiss ion to the monomer emission of the plate have been systematically examined. But the effects of the length and flexibility of a spacer are neglected,because in this simulation aromatic compounds are immobilized on a plate by the short stiff spacer. It is demonstrated that, for a functionalized plate of a short stiff sp acer in a polar solvent (in this case, the association tendency is strong, and P is close to 1), aromatic compounds of middle excitation efficiency might b e suitable as sensing elements. In addition, the immobilization density of the s ensing element should be controlled. A recommended value is about 50%.