“…Histidine (His), which is an α-amino-β-(4-imidazolyl)propionic acid, is one of the essential amino acids for humans and other mammals and plays an important role in the transport of metallic elements, synthesis of protein, growth and differentiation of cells. , Being an important biomarker of disease diagnosis and nutritional analysis, His can promote the nervous system and physical development of infants and young children and can also be used in the treatment of heart disease, anemia, and rheumatoid arthritis. , Higher or lower levels of His are closely related to human health issues, such as psychological disorders, neurological deafness, chronic kidney disease, liver failure, and Alzheimer’s disease. − Thereupon, various detection techniques have been used, and many sensing materials have been developed to detect His for providing nutrition guidance and early diagnosis of diseases. The conventional methods, such as high-performance liquid chromatography, surface-enhanced Raman spectra, electrochemistry, , colorimetry, , and fluorimetry, − are accurate, reliable, and highly sensitive, but they require sophisticated instruments and professional technicians, have unstable sensing signal in complicated biological and food samples, or need organic solvents. The developed sensing materials, such as Au nanoparticles, G-quadruplex-Cu(II) metalloenzyme, Cu nanoclusters, and metal–organic framework (MOF) materials, , still have been limited in the practical application due to complex synthesis, low sensitivity, or high cost.…”