Protein stabilized fluorescent gold nanocubes as selective probe for alkaline phosphatase via inner filter effect

We present a novel approach for the synthesis of unique template free protein stabilized gold nanocubes (PSGNCs) for sensing and quantification of alkaline phosphatase (ALP) in biological fluids. The unique wavelength independent excitation of PSGNCs and absorption of the final product of ALP catalysis, i.e., p-Nitrophenol (p-NP) at 405 nm was exploited for the inner filter effect (IFE) as a sensitive and efficient method to detect ALP. The limit of detection in aqueous solution and serum was found to be 1.616 U/L and 9.441 U/L, respectively.