The Electrochemical Sensors Based On The Modification Of Thermo-sensitive Polymers Were Used To Achieve Reversible Switched Detection Of Phenolic Substances

In recent years,with the further development of electrochemical sensing technology and the further study of material science,scientists don't content with simple materials,but are committed to research new composite modified materials to take advantage of the synergy between components in composite material for achieving better electrochemical effects.The temperature sensitive polymers can produce structural changes with the change of external temperature,so they can be modified on the electrode to show the unique intelligent detection effect.Nanomaterials are widely used in electrochemical and bioelectrochemical analysis because of their excellent electron transfer ability.This thesis,we mixed polymer and nanometer materials to get temperature sensitive polymer/nanocomposite,modified on the electrode to get the electrochemical sensors not only has temperature response characteristics,but also has the excellent electron transfer ability.By repeatedly changing the external temperature to realize the reversible "open-close" detection of the electrochemical sensor,a new direction in the field of electrochemical sensing is opened up.The main works are as follows:(1)Using free radical polymerization to synthesize the temperature-sensitive polymer PDEA,adopting the variable temperature ultraviolet-visible spectrophotometry to prove:the LCST of PDEA is 30?.(2)Evenly mixed PDEA and GO,then modified it to glassy carbon electrode to prepare a temperature response PDEA/GO/GCE electrochemical sensors.The reversible temperature sensitivity of hydroquinone in solution was investigated.When the temperature is higher than 30?,the electrochemical response signal of HQ is very strong,whitch prove that the electrochemical reaction is in a state of "on";While less than 30?,the response signal is very small,the electrochemical reaction at this time in the "off" state.And this temperature control "on-off" property is a reversible behavior.(3)The HPC/AuNPs/GCE composite modified electrode was obtained by mixing the polymer HPC and the AuNPs together.The reversible temperature switch effect of ractopamine(RAC)in the solution was studied.With the LCSTtemperature(45? of HPC is bounded,when temperature is below 45?,the response decreases sharply and the peak current is very small so the electrochemical reaction in the "off" state.And when the temperature is higher than 45?,the electron transfer between the RAC and the electrode surface is very rapid,the CV and DPV response current increase rapidly,so the modified electrodes in a state of "on".And the temperature control of HPC/AuNPs/GCE is reversible.(4)After mixing PDEA and MWCNT(COOH),the PDEA/MWCNT(COOH)/GCE electrochemical sensor with temperature-sensitive response characteristics was constructed on the surface of the glassy carbon electrode.When the temperature is over 30?,AP in PDEA/MWCNT(COOH)/GCE electrode electrochemical response signal was very strong,and the electrochemical reaction was in the "on" state;And when the temperature was below 30?,AP in PDEA/MWCNT(COOH)/GCE electrode response signal was very small,that the electrochemical reaction was in the "off" state.The temperature of the PDEA/MWCNT(COOH)/GCE electrode was reversible.