Research On The Preparation And Detection Techniques Of Biological Hydrogen Sulfide Sensor

Hydrogen sulfide（H₂S）is an important endogenous gas molecule in the human body that profoundly affects most organ systems.It plays a critical biological role in many cells,tissues,and organs.Changes in the concentration of H₂S in the breath or blood often indicate the occurrence of certain diseases.If a sensor can be developed to detect biological H₂S in real-time at room temperature,it has important research significance for improving the controllability of diseases with H₂S as biomarkers.In this paper,a series of Cu₂O based nanocomposites were prepared by a two-dimensional electrochemical in-situ deposition system and used for the construction of biological H₂S sensors.In addition,combined with the characteristics of the material,the design and construction of relevant test platform to detect its sensitive performance,and combined with relevant theories to reveal the response mechanism behind the excellent performance of the sensor.Specific research contents are as follows:（1）Cu₂O/NiO heterostructure ordered nanoarrays were prepared by in-situ electrochemical deposition method,and H₂S gas was detected at room temperature and enhanced magnetic field.The nanowire arrays were designed as a multiple potential barrier structure and exhibited strict periodicity within a few hundred micrometers.The experimental data demonstrated that under relatively weak magnetic field,the sensor showed an increase of nearly 61%in response to 50 ppm H₂S.Particularly,the effect of magnetic field enhancement on sensitivity was more significant at low concentrations（≤20 ppm）.The modulation of electrical conductivity at Cu₂O-NiO interface and surface oxygen adsorption by magnetic field are the main reasons for the enhancement of gas sensitivity.（2）A Cu₂O-carbon nanofiber（CNF）heterostructure with clearer heterojunction interface was prepared using a method similar to the above method for the detection of ultra-low concentration of H₂S gas at room temperature.The heterostructure was confirmed to have a clear interface by scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy,and voltammetry.The results showed that the detection limit of the sensor is as low as 5 ppb and can directly distinguish the exhaled gas of healthy individuals and simulated patients.The significant response to the synergistic effect of the sulfide reaction of Cu₂O and the modulation of the heterojunction barrier.（3）Cu₂O/NiO nanowire arrays were prepared for the detection of H₂S in blood（bio-H₂S）.We used a customized testing system to measure the sensor based on Cu₂O/NiO nanowire arrays.The experimental results showed that the sensor has good sensitivity,low detection limit,and good selectivity to bio-H₂S within the range of 1～200μmol/L.In addition,the excellent performance of the sensor is mainly due to the formation of Cu₂O/NiO heterostructures and sulfide reaction of Cu₂O.