Electrochemical Sensing and POC Rapid Detection Based on Functional Nanomaterials

Author:Xu Jin Qiong

Supervisor:sheng qing lin


Degree Year:2019





With the wide application in the fields of biological medicine,food safety and environmental monitoring,the analytical performance of electrochemical sensors requirements are getting higher and higher.Therefore,how to construct high performance,portable electrochemical sensors has become one of the hot issues of concern for electric analysts at home and abroad.In this paper,two non-enzyme electrochemical sensors and three electrochemical biosensors based on nanomaterials were constructed for the electrochemical detection of glucose and patulin,thereby achieving POC testing of various disease markers using blood glucose meter.This study can provide reference for the detection of disease markers and food contaminants,and can also provide reference for the application of electrochemical sensors in POC detection.The paper is divided into four chapters,and the main contributions of the author are as follows:1.Three kinds of nanomaterials,AuNP,AuNPs/Ni(OH)2 NS and AgNW@NiCo LDH,were prepared.Based on these nanomaterials,two kinds of glucose electrochemical sensors with enzyme and without enzyme were constructed,and their electrocatalytic behaviors for glucose were studied,thus establishing a new method for glucose detection.The studies showed that AuNP-CHIT provides a good microenvironment for the immobilization of GOx,which enhances the direct electron transfer efficiency of GOx.The detection limit of glucose based on the GOx-AuNP-CHIT sensor was 0.01 mM,and the linear range was 0.05-1.2 mM.AuNPs/Ni(OH)2 NS and AgNW@NiCo LDH nanocomposites exhibited excellent electrocatalytic activity for glucose oxidation.The working potential of sensor based on AuNPs/Ni(OH)2 NS was 0.5 V,the detection limit was 0.66μM,and the linear range is0.02-6.0 mM.The working potential of sensor based on AgNW@NiCo LDH was 0.4 V,The detection limit was 0.71μM,and the linear range is 0.02-6.0 mM.Both of the above enzyme-free glucose sensors have more negative working potential,so their anti-interference ability is excellent.2.BPNS nanomaterials were synthesized,then two kinds of AuNPs-BPNS nanocomposites were prepared by electrostatic adsorption and in situ reduction using BPNS as matrix material.Aptamer sensors based on BPNS,AuNPs-BPNS(electrostatic adsorption)and AuNPs-BPNS(in situ reduction)were fabricated and the methods for the detection of patulin were proposed.The researches indicated that the detection limit of patulin aptamer sensor based on BPNS was 0.50 nM,and the linear range was 1.0 nM to 1.0μM.The detection limit of aptamer sensor based on AuNPs-BPNS was 0.053 nM,and the linear range was 0.1 nM to 10.0μM.The detection limit of PAT detection by AuNPs-BPNS-based dual-signal ratio aptamer sensor was 0.043 nM,and the linear range was 0.1 nM to 100.0μM.All three sensors exhibited superior analytical performance,but the dual signal ratio sensor has a lower detection limit and a wider linear range than a single signal sensor.3.A new method for rapid detection of glutathione and triglyceride based on enzyme reaction was established by using personal glucose meter as a detection method.The detection limit of glutathione was 0.08 mM and the linear range was 0.24-1.2 mM.The detection limit of triglyceride was 0.17 mM,and the linear range was 0.5-1.5 mM.Based on the controlled release of nano-mesoporous silicon,POC testing of RNase H,mRNA and troponin is achieved.The detection limit of RNase H was 0.032 U mL-1,the linear range was 0.06-6 U mL-1;the detection limit of detection mRNA was 0.91μM,the linear range was 1.66-20.0μM;the detection limit of troponin detection was 0.067μM and the linear range is from 0.01 nM to 1.0μM.The POC testing based on the personal glucose meter has the advantages of being portable and simple in operation.