Photoelectric Anti-oxidation Capacity Research Based On Micro-nano Structure Of Novel Semiconductor Composites

Reactive oxygen species/nitrogen substances(free radicals)may be produced in aerobic cells during physiological processes such as respiration,inflammation,or under the action of certain environmental factors.At the physiological level,an appropriate number of free radicals can maintain the normal function of organisms,excessive will lead to disease.Besides,active substances can also induce lipid peroxidation cause food deterioration and corruption.The main function of antioxidants is to prevent,remove and repair the damage caused by free radicals.Since organisms are always in contact with active substances,their natural protection is often insufficient.Therefore,it is an important way to protect the human body from the damage of free radicals by supplementing the body with foods containing antioxidant substances.The foods consumed by organisms usually contain complex and diverse antioxidants,which reflect different antioxidant capacities.Therefore,the development and research of new methods for evaluating the antioxidant capacity of complex mixtures are particularly important.Nowadays,optical methods,chromatographic methods,and electrochemical methods,which have outstanding advantages and relatively mature strategies,have become routine means in food antioxidant analysis and detection.However,there are still some problems to be solved in the traditional methods,including the interference of colored substances optical methods,the overall evaluation of complex substances by chromatography,and the detection of the electrode stability electrochemical method.It is urgent to establish an accurate,convenient,and easy-to-operate new antioxidant evaluation and detection method,and photoelectric chemistry has emerged.In the construction of the entire photoelectric chemical detection platform,the photosensitive semiconductor composite material is the most important part,which determines the detection limit,sensitivity,anti-interference,and stability of the detection system.In this paper,we systematically studied the photoelectric antioxidant capacity based on the micronano structure of new semiconductor composite materials and further explored the phenomenon of antagonism and synergy in food and its causes.The main research contents are as follows:(1)Chinese herbal medicines are rich in resources and can be found in various types.The efficacy of some Chinese herbal medicines is closely related to their antioxidant effects.Therefore,the rapid and accurate evaluation of the antioxidant capacity is the foundation for the scientific utilization of Chinese herbal medicine resources.By replacing the conventional titanium dioxide(TiO2)nanomaterials with the P25(the 25 nm anatase and rutile mixed-phase titanium dioxide material),the graphitic carbon nitride(g-C3N4/P25)nanocomposite based sensitive visible light photoelectron-chemical platform has been reported herein.In this system,not only the large planar of g-C3N4 can serve as a highly dispersed carrier for the TiO2 nanomaterials,but also its highly efficient carrier transport capability can endow the composite material with excellent photoelectrochemical performance.The sensitization effect of g-C3N4 with a mass ratio of only 0.5%is the best,and the photocurrent response signal of the composite material can be increased by 4.5-fold when compared with the conventional TiO2 nanomaterials.In comparison with previous reports,the photoelectrochemical strategy not only greatly simplifies the preparation process and reduces the cost,but also effectively improves the visible light utilization efficiency.This method was used for the first time to evaluate the antioxidant capacity of traditional Chinese herbal medicines which provided a new avenue for quantifying the antioxidant performance evaluation of traditional Chinese herbal medicines.(2)Effective evaluation methods for the nutritional quality of foods that eliminate free radicals(i.e.,antioxidants)have always attracted the attention focus of scientists and even the populace.In this case,the construction of a corresponding photoelectrochemical sensor with the advantages of intuitive,rapid,and accurate assessment for global antioxidant capacity is of profound significance.In this study,the novel g-C3N4/NiS/TiO2 photoelectric sensitive platform constructed afforded the possibility for synergistic/antagonistic effect estimation among intrinsic antioxidant ingredients in food.Further investigation revealed that the internal influence of the compound structure such as redox potential and type of group on the molecular benzene ring should be the main internal reason for antioxidant synergistic behaviors.Practical application in grapefruit samples indicated that this novel antioxidant capacity evaluation idea acted as an effective candidate for nutrition assessment.Concerned photochemical strategies are expected to provide benefits for on-site foods nutrition essay which should become a guide for health care diet.