| Molecular imprinting technology?MIT?is a new technique for preparing specialized recognition media.The basic principle is that the imprinting template molecules,functional monomer and cross-linking agent were dissolved in a solvent,and were having complementary functional polymerization.After extracting the template molecules from the polymer,the polymer leaves cavities inside the polymers which are complementary in termsof size,shape,and functional groups orientation to those of the template molecules.Thus,it isshown specific selectivity and adsorption capacity of the template molecules.In particular,molecularly imprinted membrane has both advantages of the membrane and molecular imprinted polymer,so that molecularly imprinted membrane is becoming the hot topic of research in the field of electrochemical sensors.So studies are encouraged to find new methods to extend the molecularly imprinted membrane-electrochemical sensor.This paper gives a brief overview of the development of the molecularly imprinted technology?MIT?and the application of the molecularly imprinted membrane in theelectrochemical sensors.The main contents and results are summarized as follows:?1?An electrochemical sensor based on electropolymerizing o-phenylenediamine?o-PD?on a glassy carbon electrode?GCE?was developed for determination of reducing sugars.Themolecular imprinted sensor was tested by differential pulse voltammetry?DPV?to verify thechanges in peak currents of hexacyanoferrate.Under the optimum analytical conditions,the current change was linear to the logarithm of glucose and fructose concentration from 0.25 to25 ?M.The detection limit of glucose and fructose were 0.185 ?M and 0.173 ?M,respectively.Besides,the applicability of the sensitive sensor has been successfully evaluated by determining reducing sugars in the samples from sugarcane industries.?2?An enzyme free potentiometric sensor for reducing sugars?glucose and fructose?based on molecularly imprinted polymers modified on glassy carbon electrode was systematically investigated.Principle of reducing sugars detection at the molecular imprinted polymers modified on glassy carbon electrode?MIP/GCE?was ascribed to a reversible and covalent binding which was sensitive to the electrochemical potential of the prepared sensor.The imprinted polymer films introduced on the electrode surface was shown to dramatically improve the sensitivity of the sensor response.Under the optimum analytical conditions,the potential change was linear to the glucose and fructose concentration from 0.75 to 18 mM.The detection limit of glucose and fructose were 0.23 mM and 0.35 mM,respectively.Besides,the applicability of the sensitive sensor had been successfully evaluated by determining reducing sugars in the samples.?3?A sensitive and selective biosensor modified with a molecularly imprinted metallo-polymer with single-wall carbon nanotubes(PoPD/Al3+/SWCNTs/GCE)for the determination of colchicine.The biosensor was fabricated through the electropolymerization of o-phenylenediamine in the present of metal-complexing template prepolymer(the molar ratio of colchicines and Al3+ is 1: 1).Differential pulse voltammetry?DPV?,cyclic voltammetry?CV?,and UV-vis spectrometry were employed to characterize the constructed sensor.Under the optimal experimental condition,the results indicated that the biosensor based on Al3+ mediated molecularly imprinted polymer exhibited significant sensitivity and selectivity for colchicines,compared to the biosensors based on imprinted polymer without Al3+?PoPD/SWCNTs/GCE?and non-imprinted polymer with Al3+(NIPs/Al3+/SWNTs/GCE).The PoPD/Al3+/SWNTs/GCE biosensor displayed two linear relationships to the colchicine concentration in the range from 2.5×10-7 to 4.0×10-1 mol/L and from 5.0×10-6 to 2.0×10-5 M respectively.The lower limit of detection was confirmed to 9.1 ×10-8 M?S/N=3?.The biosensor demonstrated a promising feature for applying metal ion mediated MIP sensor to the measurement of colchicine in real samples. |
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