Development Of Novel Optical Detection Making Use Of Beam Deflection And Fluorescence Quenching For Real-Time In-situ Monitoring Of Materials Movements At A Vicinity Of An Aquatic Plant Surface

A novel optical detection method was developed to achieve real-time in-situ simultaneous monitoring of materials movements including dissolved oxygen(DO)and dissolved carbon dioxide(DCD)at a vicinity of micrometers from an aquatic plant surface by combining deflection of a probe beam and fluorescence quenching.In this paper,the previous experimental system was improved to correct temperature influences and to separate fluorescence and experimental LED light,a new measurement method was also made for plants monitoring.In this method,DO-quenched Ru(?)(Tris(2,2'-bipyridyl)ruthenium(?)chloride)and DCD-depended HPTS(8-Hydroxypyrene-1,3,6-trisulfonic acid)fluorescence were monitored together with beam deflection signals at the vicinity of different distance away from the plant in respiration and photosynthesis process,respectively.The materials movement was also monitored with LED changing from off to on.Experimental results showed that the materials movement in respiration had opposite trend to that in photosynthesis.DO decreased by 1.5?2 ppm,DCD increased by 1?1.5 ppm in respiration;and DO increased by 2?2.5 ppm,DCD decreased 1.1?3 ppm in photosynthesis.The system achieved the highest sensitivity at vicinity of plant surface and had fast response to materials movement when LED was turned on and off during the monitoring.The materials movements at vicinity of different organs were also monitored successfully by this method.It found a new way for plants research methods.