| Owing to their large specific surface area and ordered pore structure,porous materials have gradually become the focus of research in the field of sensing in recent years.In this thesis,porous materials were prepared via different ways and then used to construct antifouling biosensors for the quantitative detection of disease markers.The porous material with large surface area can effectively enhance the sensitivity of the sensor.Meanwhile,low fouling biosensors were constructed through the introducing of antifouling materials onto the porous structure,and accurate detection of targets was achieved in complex biological samples.The main research content is summarized as follows:(1)An antifouling sensing interface capable of sensitively assaying Immunoglobulin E(IgE)in biological samples was constructed based on the prepared porous gold.The sensing interface was fabricated through the self-assembly of a zwitterionic peptide and the Ig E aptamer onto a macroporous Au substrate,which was electrochemically fabricated with the aid of multilayer polystyrene nanospheres self-assembled on glassy carbon electrode.Due to the large surface area arising from porous morphology and high specificity of aptamer,the developed electrochemical biosensor exhibited ultrahigh sensitivity and selectivity towards IgE,with the linear range of 0.1-10 pg/mL,and a very low limit of detection down to 42 fg/m L.Interestingly,owing to the presence of the zwitterionic peptide,the biosensing interface can satisfyingly reduce the nonspecific adsorption and fouling effect.Consequently,the biosensor was successfully applied to detect IgE in complex biological samples,indicating great promise of this peptide-based sensing interface for antifouling assays.(2)Based on the immobilization of peptides and aptamers onto the nanoporous conducting polymer prepared through electrodeposition,biosensors for the detection of human immunoglobulin E(IgE)with antifouling ability were developed.The nanoporous PEDOT based sensing interface,which was prepared through the hard-template method and electrodeposition,possessed sieves-liked structure and a large surface area that can bond more biomolecules and resist the nonspecific adsorption of proteins at the same time.Based on the nanoporous structure and antifouling peptides,the biosensor was able to detect target IgE using differential pulse voltammetry(DPV)technique conveniently even in complex biological media of 20% fetal bovine serum(FBS)solution,indicating excellent antifouling property.The proposed assay provided a convenient and promising strategy for the construction of antifouling electrochemical biosensors.(3)The application of metal-organic frameworks(MOFs)in electrochemical sensing field was investigated,taking advantages of the porous and adjustable apertures of MOFs.Using electrodeposition method,the Cu-MOFs materials were facilely synthesized via a single step on the surface of an electrode.Through the combined modification of electrodes with Cu-MOFs and PEDOT,the electrochemical catalytic and sensing properties of the modified electrodes were studied.Furthermore,the MOFs material and gold nanoparticles were integrated to form a MOFs-AuNPs composite material,which possessed excellent conductivity and was used as a substrate for the subsequent assembly of biomolecules with thiol groups.The prepared electrochemical biosensor was capable of specifically recognize Immunoglobulin G(IgG)with high sensitivity and antifouling ability.The linear range of the biosensor was 0.01 to 10 ?g /m L,with a low limit of detection of 3.0ng/mL. |
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