Multicolor and photothermal dual-mode assay of alkaline phosphatase based on the UV light-assisted etching of gold nanorods.

A multicolor and photothermal dual-mode assay for sensitive alkaline phosphatase (ALP) determination was realized based on the 3,3',5,5'-tetramethylbenzidine (TMB)-induced etching of gold nanorods (AuNRs). TMB was oxidized under ultraviolet light irradiation to form TMB. In the presence of ALP, ascorbic acid phosphate (AAP) is converted to ascorbic acid, which can then reduce the levels of TMB, resulting in lower concentrations of TMB.