Electrochemical Detection Of Nitro Containing Compounds Using Metal Complexes Of Thiacalix[4]arene And Carbon Composites

In this paper,a ligand TIT4A was designed and synthesized from p-tert-butyl thiacalix[4]arene.Four coordination polymers were synthesized by solvothermal method:[Zn₂TIT4A（L1）₂]·4DMF·2Me OH（H₂L1=diphenyl ether-4,4’-dicarboxylic acid）（1）、[Zn₂TIT4A（L2）₂]·4DMF·6Me OH（H₂L2=benzophenone-4,4’-dicarboxylic acid）（2）、[Zn₂TIT4A（L3）₂]·Me OH（H₂L3=5-hydroxyisophthalicacid）（3）and[Zn₂TIT4A（L4）₂]·DMF·4Me OH（H₂L4=5-methylisophthalic acid）（4）.The four complexes were characterized by TGA,FT-IR,PXRD and elemental analysis.The structures of these four complexes were determined by X-ray single crystal diffraction technique.Among the four coordination polymers,1,2 and 3 are two-dimensional structures,and 4 is three-dimensional structure.These four complexes were combined with three carbon materials,reduced graphene oxide（rGO）,disordered mesoporous carbon（MC）and multi-walled carbon nanotubes（MWCNT）,and four composites were formed,1@rGO（1:1）,2@rGO（1:1）,3@MC（1:1）and 4@MWCNT（1:2）.Four kinds of electrochemical sensor1@rGO（1:1）/GCE,2@rGO（1:1）/GCE,3@MC（1:1）/GCE and 4@MWCNT（1:2）/GCE were obtained by modifying the glass carbon electrode with these four composites respectively.1.The detection performance of 1@rGO（1:1）/GCE and 2@rGO（1:1）/GCE on flutamide（FTA）was explored.The experimental results showed that 1@rGO（1:1）/GCE and2@rGO（1:1）/GCE could both achieve highly sensitive detection of FTA.The linear range of1@rGO（1:1）/GCE for FTA detection is 0.1-200μM,and the minimum detection limit is0.015μM;the linear range of FTA detection is 0.6-200μM at 2@rGO（1:1）/GCE,with a minimum detection limit of 0.15μM.These two electrochemical sensors have good reproducibility,stability and anti-interference,and have good recovery rate for FTA in real samples of lake water,human urine and serum.Among them,1@rGO（1:1）/GCE FTA has a lower detection limit,possibly because 1@rGO（1:1）/GCE has a larger effective active area,which makes its electrocatalytic ability stronger than 2@rGO（1:1）/GCE.2.The detection performance of 3@MC（1:1）/GCE and 4@MWCNT（1:2）/GCE for nitrobenzene（NB）was explored.The experimental results show that 3@MC（1:1）/GCE and4@MWCNT（1:2）/GCE can achieve highly sensitive detection of NB.The linear range of NB detection is 1.0-200μM at 3@MC（1:1）/GCE,and the minimum detection limit is 0.065μM;the linear range of NB detection at 4@MWCNT（1:2）/GCE is 1.0-300μM with the lowest detection limit of 0.045μM.These two electrochemical sensors have good reproducibility,stability and anti-interference,and also have good recovery effect for the detection of NB in real samples.There is little difference between the two kinds of sensors in detecting NB.