Research Of Graphene Imprinted Carcinogenic Aromatic Amines Using Zero Current Potentiometry

Molecular imprinting technique is widely used in testing analysis for its high selectivity,specific absorption and the characteristics of long service life.Zero current potentiometry is a new interface potential sensing technology that can test and analyze rapidly and sensitively based on the zero current potential change on electrode interface.Graphene is a new type of nanometer materials with high conductivity and high specific surface area.4-aminobiphenyl,Benzidine,2,4-Dimethylaniline,M-Anisidine and O-tolidine are five kinds of inherent aromatic amide that do harm to human beings and our surrounding environment,so the detection and research for them would be significant.This article prepared the molecularly imprinted polymer(MIP)of above five kinds of inherent aromatic amide on the surface of electrode of pencil leads or graphene modified pencil leads respectively with electric polymerization,using zero current potentiometry,molecularly imprinted polymer electrochemical sensor have high recognition of each template molecules.The specific research Content as follows:(1)Using electric polymerization,prepared 4-amino biphenyl molecularly imprinted polymer in pencil lead electrode surface with acrylic acid as functional monomer,4-amino biphenyl as template molecules.While getting the 4-amino biphenyl molecularly imprinted polymer pencil lead electrode for elution template molecules,using zero current potentiometry to optimize the preparation conditions,and studying the electrode to test and analysis 4-aminobiphenyl.The results showed that when the concentration of 4-aminobiphenyl is during 5×10-9～5×10-5 mol·L-1,the relationship between electrode zero current value and the concentration of 4-aminobiphenyl is linear in logarithmic scale.The linear equation is:EZCP=0.015551og[4-ABP]+0.20868(R=0.994,n=9),with detection limit 1.07×10-9 mol·L-1,and it is of strong anti-interference.The electrodes are used to detect the actual sample shows the coefficient of sample recovery is in the ranges of 98%101.6%.(2)Benzidine on electric polymerization method,the benzidine molecularly imprinted polymers were synthesized in pencil lead electrode and graphene modified pencil electrode surface by electropolymerization using benzidine as the monomer,methyl methacrylate as the template molecule.While getting the benzidine molecularly imprinted polymer pencil lead electrode(BZ-MIPs/PEC)and graphene modified pencil electrode(BZ-MIPs/G-PEC)for elution template molecules,using zero current potentiometry(Ezcp)to studying the electrode to test and analysis benzidine.The results showed that the EZCP of the BZ-MIPs/PEC and BZ-MIPs/G-PEC showed a good linear relationship with the logarithmic concentration of the benzidine.However the BZ-MIPs/G-PEC detection range width than BZ-MIPs/PEC detection range,BZ-MIPs/G-PEC detection range was 4×10-8～1×10-5 mol·L-1,BZ-MIPs/PECdetection range was 8×10-8～8X10-6 mol·L-1,BZ-MIPs/G-PEC detection limit of 1.89×10-8 mol·L-1 was low than BZ-MIPs/PEC detection limit.The BZ-MIPs/G-PEC was used in the determination of synthesized samples,the recoveries could reach 96.2%～104.2%.(3)The imprinted polymerization was prepared on the graphene modified pencil electrode surface by using electropolymerization method with acrylic acid as functional monomer,2,4-Dimethylaniline as template molecules.The 2,4-Dimethylaniline molecularly imprinted polymer graphene modified pencil electrode(2,4-DMA-MIPs/G-PEC)was test and analysis 2,4-Dimethylaniline by zero current potentiometry(Ezcp).The results showed that when the concentration of 2,4-Dimethylaniline is during 1×10-9～5×10-6mol · L-1,the relationship between Ezcp of 2,4-DMA-MIPs/G-PEC showed a good linear relationship with the logarithmic concentration of 2,4-Dimethylaniline.The linear equation is:EzCP=0.005371og[2,4-DMA]+0.1989(R=0.991,n=8),with detection limit 3.35×10-10 mol·L-1.The electrode use time is more than 20 days,recoveries could reach 95.6%～101.7%.(4)Acrylamide as functional monomer,o-methoxyaniline as template molecules,o-methoxyaniline molecularly imprinted polymers graphene modified pencil electrode(OMA-MIPs/G-PEC)was prepared on graphene modified pencil electrode surface by electropolymerization,using zero current potentiometry to optimize the preparation conditions,and studying the electrode to test and analysis o-methoxyaniline.The results showed that when the concentration of o-methoxyaniline is during 1×10-9～5×10-5mol·L-1,the relationship between Ezcp of OMA-MIPs/G-PEC showed a good linear relationship with the logarithmic concentration of o-methoxyaniline.The linear equation is:EZCP=-0.02567log[OMA]-0.10405(R=0.995,n=10),with detection limit 6.43 × 10-10mol·L-1.The standard deviation of the electrode to detect less than 1.65%,and recoveries could reach 95.2%～105.7%.(5)The o-tolidine molecularly imprinted polymers based on electrochemical sensor for sensitive detection of o-tolidine was prapased in this article.The imprinted polymerization was prepared on the graphene modified pencil electrode surface by using electropolymerization method with acrylamide as functional monomer,o-tolidine as template molecules.The o-tolidine molecularly imprinted polymer graphene modified pencil electrode(o-TD-MIPs/G-PEC)was test and analysis o-tolidine by zero current potentiometry(Ezcp).The results showed that when the concentration of o-tolidine is during 1×10-9～1×10mol·L-1,the relationship between Ezcp ofo-TD-MIPs/G-PEC showed a good linear relationship with the logarithmic concentration of o-tolidine.The linear equation is:EZCP=-0.007151og[o-TD]+0.08951(R=0.991,n=7),with detection limit 8.07 X 10-10mol·L-1.The electrodes are used to detect the actual sample shows the coefficient of sample recovery is in the ranges of 96.5%～103.1%.