Rapid Determination Of The Biomarker Based On Multispectral Imaging Technology

Biomarker is a kind of signal index referring to diseases,biological states and natural environment conditions of human body.It is widely used in the fields of disease prediction and diagnosis,effectiveness evaluation of drugs and environmental exposure assessment.Hair has been widely recognized as an ideal biomarker for assessing diseases,environment,drugs and poisons because of its inherent advantages of easy collection and transportation,stability,low preservation cost,and ease of acceptance.Ultraviolet in the sunlight is crucial to human health since it may have detrimental effects on an individual's health when there is a deficiency or excess.Human hair is exposed to the outermost layer of the skin,which is more vulnerable to UV radiation relative to skin.Therefore hair can act as a target organ for UV irradiation evaluation.UV irradiation leads to different degrees of hair photodamage,which is regarded as an important indicator to evaluate the extent of sunlight exposure.In this thesis,the morphology of surface fibers of segmented hair samples was qualitatively analyzed by multispectral imaging(MSI)technology and further characterized with SEM micrographs.We found that the hair segments with longer growing time showed more severe photodamage and significantly higher reflectance value of MSI in near-infrared region.The multispectral reflectance value of hair segments with different growing time could be precisely reproduced by exposing the same hair root segment to specific durations of UV irradiation,suggesting that MSI could be applied to evaluate the photodamage of the hair and provide theory basis for modeling the extent of UV exposure.On the other hand,the heavy metal content in hair can assist in assessing the level of heavy metal exposure and heavy metal content in human body.The heavy metal accumulation on hair surface fibers was also qualitatively analyzed by MSI technology,which showed that the reflectance value of hair samples in 505 ~ 700 nm decreased with the increasing heavy metal accumulation.Moreover,the reflectance value of near tip hair samples changed more significantly,indicating that the near tip hair samples may absorb more heavy metal ions and in turn induced much more serious hair damage.The result showed that MSI technology could be applied to detect the variation of hair heavy metal accumulation and provide the possibility to build a model for assessing the degree of heavy metal concentration.This work fulfils the fundamental research for evaluation of photodamage and heavy metal accumulation of hair,and therefore provides a theoretical basis for applying MSI technology to the field of UV radiation assessment,environmental exposure,heavy metal detection,forensic identification,drugs and toxic exposure later.