Development And Application Of Graphene-Platinum/Gold Hydrogen Peroxide Sensor

Hydrogen peroxide?H₂O₂?acts as the second messenger in cells,plays a critical role in signal transduction within and between cells.Whether the concentration level is normal or not is closely related to the normal physiological activities of the cells?including stem cells and various functional cells?and the occurrence of the disease.Therefore,it is of great significance to develop an accurate and effective sensor for detecting H₂O₂ in the cell microenvironment.In this paper,laser-induced graphene was prepared based on laser direct writing technology,and the H₂O₂ sensor was prepared by loading noble metal nanoparticles on the surface of LIG,which realized the detection of H₂O₂ in the cell microenvironment.The specific research contents are as follows:Firstly,the polyimide film?PI?and Nomex paper were transformed into laser-induced graphene?LIG?by laser direct writing technology,and LIG were characterized.The results showed that the prepared LIG conformed to the characteristics of graphene.Morphological characterization shows that the prepared LIG is bulky,has a large specific surface area,and has the characteristics of few layers.Raman spectroscopy indicates that the peak position and intensity of the LIG characteristic peak are consistent with the characteristic peak of graphene.Secondly,the PtLIG enzyme-free H₂O₂ sensor was prepared by sputtering platinum nanoparticles?PtNPs?thin film on the surface of PI-based LIG by magnetron sputtering.The linear range is 0.5?M-5 mM,the detection limit is 0.1?M,the sensitivity is 248.4?AmM^-1cm^-2.Gold nanoparticles?AuNPs?were deposited on the surface of Nomex paper-based LIG by double pulse electrodeposition to construct H₂O₂ sensor.The linear range of the sensor is 0.4?M-0.5 mM with a detection limit of 0.05?M,sensitivity of 310?AmM^-1cm^-2.Finally,the AuLIG sensor was integrated with the microfluidic chip and detected for the H₂O₂ in the microenvironment of Hela cells in the microfluidic chip stimulated by ascorbic acid?AA?.The results showed that about 191 amol of H₂O₂ was released per cell under 3?M AA stimulation.The prepared sensors have simple preparation process,easy availability,strong anti-interference,high sensitivity,low detection limit and wide linear range.It can realize the detection of H₂O₂ in the cell microenvironment,which has certain superiority compared with the performance of the existing sensor.It is of great significance for monitoring the functional state of cells and tissues,and has potential application value in disease diagnosis.