Electrochemical Response Studies On Irritating Polymers/nanocarbon Materials

Electrochemical method is an attractive for sensing owing to its advantages of sensitivity,simplicity,easy miniaturization.In this paper,the required temperature-sensitive macromolecules were synthesized by RAFT method,and then mixed with carbon nanomaterials to prepare temperature-responsive electrochemical sensors with excellent performance.（1）PHNM was synthesized via free radical polymerization by using N-（2-hydroxyethyl）acrylamide,N-isopropylacrylamide,methacrylamidopropyl trimethyl ammonium chloride as monomer,EDMAT as chain transfer agent,TPO as chain initiator.Then it was reacted with cinnamic acid to obtain PCHNM.GPC and¹H-NMR tests indicated that the polymer PCHNM has been successfully prepared.（2）The PCHNM/C₆₀/GCE possessing temperature response to[Fe（CN）₆]^3-was obtained by modifying the electrode with C₆₀and PCHNM.When the aqueous solution was above the LCST,which causes the the PNIPAM segment contained in PCHNM shrinked.The cation end of the quaternary ammonium salt in the polymer PCHNM was brought close to the electrode surface.The anion[Fe（CN）₆]^3-was adsorbed on cation end by electrostatic action,the carbon material C₆₀was used to promote the conduction of electrons on the electrode surface,so its peak current increases.When the temperature is lower than LCST,the PNIPAM chain expanded,The anion[Fe（CN）₆]^3-was away from electrode surface,and the peak current decreases.Then the electrochemical response analysis of the temperature adjustment effect of[Fe（CN）₆]^3-was realized through the synergistic effect of the block polymer and C₆₀.（3）The temperature-sensitive film PCHNM/GC was prepared by mixing C₆₀and GO,and then interacting with PCHNM.At 42℃,the PNIPAM segment in PCHNM solution collapse,which enhances the transfer of PCHNM/GC on the electrode surface,probe dopamine showed a better electrochemical signal.At 16℃,due to the swell of the PNIPAM chains in this polymer.The electronic conduction of DA on the electrode surface was cut off,and the peak current was reduced.In summary,we have obtained a composite membrane PCHNM/GC with a temperature-responsive electrochemical recognition for DA.（4）Two kinds of sensors（P/GS/GCE and PGS/GCE）with different temperature responses on electrochemical recognition of hydroquinone were fabricated using different feed sequences based on short multi-walled carbon nanotubes（SMWCNTs）,graphene oxide（GO）and poly（N-isopropylacrylamide）₁₀₁-b-poly（2-acrylamidoethyl benzoate）₃₇(PNIPAM₁₀₁-b-PAAEB₃₇).And the temperature-responsive electrochemical of HQ/CC was identified by the synergistic action between the carbon material and the polymer.P/GS film:When T>LCST,the polymer collapses and covers the electrode surface,which cut off the electronic conduction of HQ/CC on the electrode surface,and the peak current was reduced.When T<LCST,HQ/CC passes through the polymer chains and undergoes a redox reaction on the electrode surface,and the peak current increases.PGS film:When T>LCST,because the distance between the carbon materials was shortened,the carbon material can promote HQ/CC to carry out the redox reaction on the electrode surface,and the peak current increases.When T<LCST,the distance between the carbon materials was lengthened,HQ/CC cannot perform the redox reaction on the electrode surface through the carbon materials,and the peak current was reduced.From the above,we have successfully prepared two different temperature-responsive films（P/GS and PGS）with a temperature-responsive electrochemical recognition for HQ/CC.