Construction Of N-Docosane/Silica/Polypyrrole/MOFs Multilayer Phase Change Microcapsules And Its Application In Biosensors

Dopamine is widely present in the endocrine system,kidneys,cardiovascular system and central nervous system of humans and animals.It is a neurotransmitter belonging to the catecholamine family.Its content is closely related to neurological disorders.Therefore,it is used in the diagnosis of various diseases,It is very necessary to accurately and sensitively detect the content of dopamine.However,traditional analytical methods such as high performance liquid chromatography,capillary electrophoresis,chemiluminescence,etc.require special instruments,long working time,cumbersome pretreatment,and high relative costs.Electrochemical measurement methods have higher sensitivity,Quick response,low cost,easy operation and real-time response are considered to be an effective means of detecting dopamine.In this paper,a MOFs/PPy/enzyme-modified electrochemical biosensor with in-situ temperature control is designed.By combining phase change materials,functional materials and enzymes to modify electrodes,it not only has excellent detection performance,but also can work in a wider temperature range.In the whole preparation process,according to the best working temperature(45?)of the biological enzyme,n-docosane with a phase transition temperature of 44.5?was matched,and the phase change material was used as the core material,and the high biological affinity two Silica/polypyrrole is the shell layer,and the modification of the multilayer shell material significantly improves the thermal stability and conductivity,thereby promoting electron transport;subsequently,ZIF-8 particles are introduced on the shell layer with polypyrrole as the binding site.Unsaturated metal coordination can provide more catalytically active sites,and can have good selectivity to specific small molecule analytes dopamine through the size repulsion effect,and a large surface area can be used to enrich electrons,thereby amplifying the electrical signal response;Finally,the bioenzyme is combined with the functional material by the drip coating method,and after two-step electronic signal amplification,an electrochemical biosensor that can efficiently detect dopamine is obtained.The results show that in this experiment,by combining ZIF-8 with conductive materials,the synergy of the two makes the sensitivity of electrochemical biosensors greatly improved.Combining phase change materials with biological enzymes improves the performance of electrochemical biosensors.The thermal stability also expands its working temperature range,which makes it more practical in the process of detecting dopamine.