Preparation And Electrochemical Sensing Performances Of 2D Ti₃C₂T_x/NiCoP Composite

Dopamine(DA)is an important catecholamine neurotransmitter in the human body,playing a crucial role in the functions of the kidneys,metabolism,cardiovascular and central nervous systems.Abnormal levels of dopamine concentration may lead to neurological disorders and various diseases such as schizophrenia,Parkinson’s disease,and Alzheimer’s disease.Therefore,the accurate detection of DA is of great significance to the development of biomedical science and human health.Currently,electrochemical methods are widely used for DA detection due to their advantages of high sensitivity,high accuracy,wide measurement range,low cost,and simple operation and instrument tuning.Various electrode modification materials have been developed for quantitative detection of DA,but the sensing performance of a single electrode material itself often cannot meet the application requirements.Therefore,this paper aims to achieve highly sensitive sensing of DA by developing new high-performance electrode materials.The main research contents are as follows:Two-dimensional Ti3C2Tx nanosheets have been widely used in the field of electrochemical sensors due to their high conductivity,large surface area,and good biocompatibility.In this study,the acid etching method(LiF and concentrated hydrochloric acid mixture solution)was used to remove the Al layer in the Ti3AlC2 precursor,and the resulting green colloidal solution was obtained by ultrasonic stripping.After freeze-drying,two-dimensional Ti3C2Tx aerogels were obtained.Different concentrations of the prepared twodimensional Ti3C2Tx colloidal solution were used to construct modified electrodes for DA detection,and the optimal concentration and potential were explored.The sensitivity,detection limit,and linear detection range of the material for DA detection were 0.043 μA μM-1 cm-2,0.13 μM(S/N=3),and 0.85-480 μM,respectively.However,the layer stacking problem of two-dimensional Ti3C2Tx nanosheets inevitably occurs during electrode construction,which limits their performance.Therefore,introducing other materials onto the surface of two-dimensional Ti3C2Tx,the interlayer stacking problem can be further improved.Compared with NiCo2O4,NiCoP has better conductivity and catalytic activity,and has become an efficient catalyst material in recent years.Different shapes of NiCoP were prepared by various processes in this study.However,the aggregation problem of NiCoP greatly limits its application in the sensor field.After combining NiCoP with two-dimensional Ti3C2Tx,not only was the aggregation of both materials suppressed,but it was also found that the morphology of NiCoP changed from a sea urchin-like shape to dispersed nanowires.The sensitivity,detection limit,and linear detection range of the Ti3C2Tx/NiCoP composite material for DA detection were 0.1993 μA μM-1 cm-2,0.028 μM(S/N=3),and 0.17-564 μM,respectively.Two-dimensional Ti3C2Tx nanosheets provide good conductivity,and the in-situ growth of NiCoP nanowires on their surface exposes more reactive sites,and the synergistic effect of the two materials improves the electrochemical performance of the composite material.To address the issues of poor conductivity and easy agglomeration of Ti3C2Tx and NiCoP after being combined,this study introduces carbon cloth(CC)as a substrate material with excellent conductivity,high stability,and good flexibility.CC/Ti3C2Tx/NiCoP composite material is prepared via hydrothermal and phosphorization methods.The sensitivity,detection limit,and linear detection range of CC/Ti3C2Tx/NiCoP composite material in detecting dopamine are 31.4101 μA μM-1 cm-2,0.18 nM(S/N=3),and 0.17-784.55 μM,respectively.The excellent performance of CC/Ti3C2Tx/NiCoP composite material in dopamine detection is explained by analyzing its electrical conductivity,hydrophilicity,and electrochemically active surface area(ECSA).The composite integrated the advantages of large specific surface area of zero-dimensional NiCoP quantum dots,rich electrochemical active sites of one-dimensional porous NiCoP nanowires,hydrophilicity of two-dimensional Ti3C2Tx nanosheets,and high conductivity of three-dimensional CC substrate,thus,the detection performance of the composites for DA is significantly improved.