Construction Of Gold Nanoparticles-Based Array Sensors And Study On Biomolecular Differentiation Performance

Biomolecules such as biothiols and proteins are closely related to many physiological functions.The qualitative and quantitative detection of these biomolecules is of great significance for early diagnosis and diseases evaluation.As a cross-responsive sensing method,array sensor has the advantages of high-throughput,fast analysis speed and high sensitivity,which is suitable for simultaneous determination of multiple analytes.In this paper,different types of array sensors are constructed based on different biomolecules.We investigate the difference of spectral response between sensor units and analytes,and explore the ability of array sensor to distinguish different kinds of biothiols and proteins.Verify the practical application potential of constructed array sensor.The specific research content and results are as follows:1.Preparation of gold nanoparticles（AuNPs）by sodium citrate reduction method.The AuNPs-metal ion-o-phenylenediamine（OPD）colorimetric array sensor was constructed by combining with three metal ions(Ag⁺,Cu²⁺,Hg²⁺)and OPD respectively.Different sensing units were used to interact with biothiols differently to induce OPD catalytic oxidation reaction and change AuNPs aggregation state,resulting in the discrimination of different biolthiols with the concentrations as low as 10 nM.In addition,the array sensor can realize the discrimination of different concentrations（50 nM,1μM）of biothiols and different proportions（0:10,1:9,5:5,9:1,10:0）of mixed biothiols samples,which has a certain application value in complex matrix environment.2.Different surface functionalized MoS₂ QDs were prepared by using three biothiols（glutathione,L-cysteine,N-acetyl-L-cysteine）and sodium molybdate as precursors.AuNPs/MoS₂ QDs dual-spectral array sensor was constructed.Through the construction of array sensors based on single MoS₂ QDs and multiple MoS₂ QDs and the comparison of distinguishing performance,it is proved that increasing the number of sensor units is important to improve the detection sensitivity.Based on the difference of electrostatic adsorption between different proteins and sensing units,five proteins with concentrations as low as 10 nM were distinguished.Meanwhile,the array sensor can be used to distinguish the proteins with different concentrations（50 nM,200 nM,1μM）and binary protein mixed samples with different molar ratios（0:10,3:7,5:5,7:3,10:0）at total concentration of 500 nM.In addition,the quantitative detection of Lys can be achieved in the concentration range of 10～500 nM.This array sensor possesses the potential to differentiate proteins in the complex urine sample environment.