Silicon quantum dots with tunable emission synthesized via one-step hydrothermal method and their application in alkaline phosphatase detection

•The hydrophilic SiQDs were synthesized via one-step hydrothermal method only using APS and acrylic acid.•Controlling the fluorescent color of SiQDs easily by adjusting the pH value of reaction system.•ALP activity was detected base on the fluorescence quenching of SiQDs with good linear relationships.•The SiQDs were stable in physiological environment and have good anti-interference ability. Alkaline phosphatase (ALP) plays an important role in normal growth. Many diseases will occur if the content of ALP is abnormal. Hence, the development of convenient and sensitive assay for monitoring ALP is extremely important. In this work, hydrophilic silicon quantum dots (SiQDs) with tunable emission were synthesized via hydrothermal method. The fluorescent emission of SiQDs was changed easily by adjusting the pH value of reaction system. The detection of ALP activity has been developed by measuring the fluorescence quenching of SiQDs. Quantitative limited evaluation of ALP activity was 1 U/L and the linear relationship was 1 U/L to 7500 U/L. Meanwhile, the fluorescent of as-prepared SiQDs were stable in physiological environment and embodied an excellent anti-interference of ions. High sensitivity and wider detection range, the proposed assay is capable of proved that they could serve as a new species of fluorescence probes for biosensors.