A new sensing system for the detection of photosynthetic herbicides in water has been developed, based on the use of a trans-membrane protein complex, the reaction centre (RC) isolated from Rhodobacter sphaeroides. The stationary and excited state of this protein are characterised by different absorption properties. The path followed by the protein to return to the stationary state is influenced by the presence of photosynthetic herbicides. Therefore the concentration of herbicides could be measured by monitoring the temporal changes of absorption following optical excitation. An optoelectronic system, which makes use of a 860 nm light emitting diode and a hybrid photodetector, is coupled to a 5 cm-long optical cell containing the RC solution through optical fibres. The system was tested with atrazine and a limit of detection of 10 nM was obtained.
Time-resolved absorption as optical method for herbicide detection
Baldini F;Domenici C;Giannetti A;Mencaglia A
2003
Abstract
A new sensing system for the detection of photosynthetic herbicides in water has been developed, based on the use of a trans-membrane protein complex, the reaction centre (RC) isolated from Rhodobacter sphaeroides. The stationary and excited state of this protein are characterised by different absorption properties. The path followed by the protein to return to the stationary state is influenced by the presence of photosynthetic herbicides. Therefore the concentration of herbicides could be measured by monitoring the temporal changes of absorption following optical excitation. An optoelectronic system, which makes use of a 860 nm light emitting diode and a hybrid photodetector, is coupled to a 5 cm-long optical cell containing the RC solution through optical fibres. The system was tested with atrazine and a limit of detection of 10 nM was obtained.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
