Preparation Of Functional Gold Nanocomposites And Their Applications In Biomolecule Detection

ObjectiveGold nanomaterials have attracted wide attention because of their high electrical conductivity,good biological inertness,large specific surface area and strong X-ray absorption coefficient.In recent years,gold nanomaterials have been increasingly used in various fields,and the research on gold nanometers and their composite materials has also made great progress.In this article,the electrochemical reduction method is used to prepare gold nanoparticles,and for the first time gold nanoparticles（AuNPs）are combined with a new conductive polymer poly（3,4-ethylenedioxythiophene）:polystyrenesulfonate（PEDOT:PSS）,established an ultra-sensitive signal amplification platform,and successfully applied it to the ultra-sensitive detection of tumor suppressor gene p53 protein and alkaline phosphatase（ALP）.MethodsThe electrochemical cyclic voltammetry was used to reduce chloroauric acid（HAu Cl4）to prepare gold nanoparticles while introducing the highly conductive polymer PEDOT:PSS.The two nanomaterials were combined and modified on the surface of the glassy carbon electrode to establish a new signal amplification platform.Using ZIF-8 as the carrier for encapsulating the redox probe DAP and connecting the antibody 2（Ab2）,a new type of immunoprobe（ZIF-8-DAP–Ab2）was prepared.And electrochemical differential pulse voltammetry（DPV）was used to measure the electrochemical signal,which realized the ultra-sensitive detection of p53 protein.Signal amplification platform based on AuNPs/PEDOT:PSS.Using 1-naphthophosphate sodium salt as the hydrolysis substrate,the process of oxidizing the hydrolyzed product of ALP 1-naphthol to 1-naphthoquinone will release a current response signal.The electrochemical signal was measured by DPV,which realized the ultra-sensitive detection of ALP.ResultsBased on the preparation of gold nanoparticles and polymer PEDOT:PSS complex,and the design of the ZIF-8-DAP–Ab2 immunoprobe,an ultra-sensitive electrochemical analysis system was established to realize the detection of tumor suppressor gene p53 protein.In the buffer solution with p H=7.5,the concentration range of p53 is 1～120 ng m L^–1,and the electrochemical response produced has a good linear relationship with the concentration,and the detection limit is 0.09 ng m L^–1.This method has good reproducibility,specificity,stability and recovery rate.The electrochemical analysis system established based on gold nanoparticles and polymer PEDOT:PSS greatly amplifies the current response signal generated by the hydrolyzate of ALP oxidized 1-naphthol,thus realizing the detection of ALP.The detection range of this method for ALP is 0.1～120 U L^–1,and the detection limits are 0.03 U L^–1 through the linear relationship between the electrochemical signal response and the concentration.Compared with other electrochemical sensors,the prepared electrochemical analysis system has a wider detection range and a lower detection limit.ConclusionsIn this paper,an electrochemical sensing system based on gold nanoparticles and polymer PEDOT:PSS was established to detect the tumor suppressor gene p53 protein and ALP.It has the advantages of simple operation,large specific surface area,strong electrical conductivity,which can greatly enhance the detection sensitivity and reduce the detection limit.It can not only sensitively detect p53 protein and ALP,but also provide another feasible strategy for the detection of other biomolecules.