title: Stimulus Response of Au-NPs@GMP-Tb Core-Shell Nanoparticles: Toward Colorimetric and Fluorescent Dual-Mode Sensing of Alkaline Phosphatase Activity in Algal Blooms of a Freshwater Lake.
abstract: In this study, we demonstrate a colorimetric and fluorescent dual-mode method for alkaline phosphatase activity (APA) sensing in freshwater lake with stimuli-responsive gold nanoparticles@terbium-guanosine monophosphate (Au-NPs@GMP-Tb) core-shell nanoparticles. Initially, the core-shell nanoparticles were fabricated based on Au-NPs decorated with a fluorescent GMP-Tb shell. Upon being excited at 290 nm, the as-formed Au-NPs@GMP-Tb core-shell nanoparticles emit green fluorescence, and the decorated GMP-Tb shell causes the aggregation of Au-NPs. However, the addition of ALP destroys GMP-Tb shell, resulting in the release of Au-NPs from the shell into the solvent. As a consequence, the aggregated Au-NPs solubilizes with the changes in the UV-vis spectrum of the dispersion, and in the meantime, the fluorescence of GMP-Tb shell turns off, which constitutes a new mechanism for colorimetric and fluorescent dual-mode sensing of APA. With the method developed here, we could monitor the dynamic change of APA during an algal bloom of a freshwater lake, both by the naked eye and further confirmed by fluorometric determination. This study not only offers a new method for on-site visible detection of APA but also provides a strategy for dual-mode sensing mechanisms by the rational design of the excellent optical properties of Au-NPs and the adaptive inclusion properties of the luminescent infinite coordination polymers.
authors.affiliation: School of Ecological and Environmental Sciences and ‡Department of Chemistry, East China Normal University , 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Ecological and Environmental Sciences and ‡Department of Chemistry, East China Normal University , 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Deng
authors.affiliation: School of Ecological and Environmental Sciences and ‡Department of Chemistry, East China Normal University , 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Yumeng
authors.initials: Y
authors.lastname: Xue
authors.affiliation: School of Ecological and Environmental Sciences and ‡Department of Chemistry, East China Normal University , 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Guoyue
authors.initials: G
authors.lastname: Shi
authors.affiliation: School of Ecological and Environmental Sciences and ‡Department of Chemistry, East China Normal University , 500 Dongchuan Road, Shanghai 200241, China.
authors.forename: Tianshu
authors.initials: T
authors.lastname: Zhou
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis*; D003124:Colorimetry / Q000379:methods; D005068:Eutrophication; D006046:Gold; D006157:Guanosine Monophosphate; D060106:Lakes / Q000382:microbiology; D053768:Metal Nanoparticles; D011108:Polymers; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D013725:Terbium
chemical_list: D011108:Polymers; D013725:Terbium; D006046:Gold; D006157:Guanosine Monophosphate; D000469:Alkaline Phosphatase