Research On The Application Of Rare Earth Nanomaterials In The Detection And Scavenging Of Reactive Oxygen Species

Reactive oxygen species?ROS?can be used to kill cancer cells,due to the irreversible damage induced by interacting with DNA proteins and lipids.Excessive ROS inevitably lead to the death of surrounding normal cells and tissues and cause a series of oxidative stresses related diseases,such as liver damage.ROS are currently known as one of the most toxic substances to organisms.Therefore,studies involving reactive oxygen species have become important research topics in the fields of biology,biochemistry,and biomedicine.Here,the thesis project consists of two parts.The first part is the detection of·OH in living cells or liver tissue with high selectivity and sensitivity.The second part is scavenging excess ROS by Au@CeO₂ NRs to protect surrounding normal cells.Introduction of the first part:Two-photon imaging possesses significantly advantages over the general one-photon imaging due to its high spatial resolution,low photo damage and deep tissue penetration properties.Herein,we designed a highly selective and sensitive hydroxyl radical nanoprobe based on the luminescence resonance energy transfer?LRET?between upconversion nanoparticle and methylene blue?MB?.The concentration of·OH could be determined by the fluorescence recovery of the upconversion nanoparticle due to the oxidative damage of MB.Using this nanoprobe,the·OH in living cells or in liver tissues could be monitored using two-photon light as the exciting light to realize high sensitivity and selectivity.The second part mainly introduces the intrinsic protection mechanism of catalytic nanomaterials for removing excess ROS.As one of the most common metals for catalysis,the high surface area to volume ratio of Au is ideal for maximizing catalytic activity.Meanwhile,CeO₂,which is widely used in the decomposition of peroxides,is known for its antioxidant activity.Therefore,the Au@CeO₂ NRs with good biocompatibility and ROS-eliminating ability could be used as a high-efficiency PPT material for cancer treatment without inducing ROS related side effects.