TIME-RESOLVED FLUORESCENCE DETECTION METHOD BASED ON PHASE-EQUALIZATION FREQUENCY MULTIPLICATION MODULATION PRINCIPLE

摘要

A time-resolved fluorescence detection method based on a phase-equalization frequency multiplication modulation principle. The method comprises: triggering fluorescence by acting on a subject matter to be detected through a base-frequency signal modulation excitation light source to enable the fluorescence to be periodically enhanced and attenuated; controlling a sampling period through a double-frequency square wave signal to divide both a fluorescence rising period and a fluorescence attenuation period into two portions; and respectively performing independent sampling thereon, then calculating a sampling difference value between the two portions, and performing addition to obtain an intensity representative value of a fluorescence signal, so as to obtain a concentration value of the subject matter to be detected. The method can not only eliminate fluorescence interference of a substrate in a sample, but can also eliminate signals, such as environmental background light and power frequency interference of space electromagnetic waves, thus improving the intensity of a fluorescence measuring signal for detecting the sample; and the method is superior to a conventional time-resolved fluorescence method, and can be applied to fluorescence intensity detection of subject matters in many fields, such as biology, chemistry and medicine.