title: Design and synthesis of target-responsive hydrogel for portable visual quantitative detection of uranium with a microfluidic distance-based readout device.
abstract: Due to uranium's increasing exploitation in nuclear energy and its toxicity to human health, it is of great significance to detect uranium contamination. In particular, development of a rapid, sensitive and portable method is important for personal health care for those who frequently come into contact with uranium ore mining or who investigate leaks at nuclear power plants. The most stable form of uranium in water is uranyl ion (UO2(2+)). In this work, a UO2(2+) responsive smart hydrogel was designed and synthesized for rapid, portable, sensitive detection of UO2(2+). A UO2(2+) dependent DNAzyme complex composed of substrate strand and enzyme strand was utilized to crosslink DNA-grafted polyacrylamide chains to form a DNA hydrogel. Colorimetric analysis was achieved by encapsulating gold nanoparticles (AuNPs) in the DNAzyme-crosslinked hydrogel to indicate the concentration of UO2(2+). Without UO2(2+), the enzyme strand is not active. The presence of UO2(2+) in the sample activates the enzyme strand and triggers the cleavage of the substrate strand from the enzyme strand, thereby decreasing the density of crosslinkers and destabilizing the hydrogel, which then releases the encapsulated AuNPs. As low as 100nM UO2(2+) was visually detected by the naked eye. The target-responsive hydrogel was also demonstrated to be applicable in natural water spiked with UO2(2+). Furthermore, to avoid the visual errors caused by naked eye observation, a previously developed volumetric bar-chart chip (V-Chip) was used to quantitatively detect UO2(2+) concentrations in water by encapsulating Au-Pt nanoparticles in the hydrogel. The UO2(2+) concentrations were visually quantified from the travelling distance of ink-bar on the V-Chip. The method can be used for portable and quantitative detection of uranium in field applications without skilled operators and sophisticated instruments.
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Yishun
authors.initials: Y
authors.lastname: Huang
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Luting
authors.initials: L
authors.lastname: Fang
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China. Electronic address: zhuzhi@xmu.edu.cn.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Ma
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Leiji
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Xiamen Entry-Exit Inspection and Quarantine Bureau, Xiamen 361026, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Xiamen Entry-Exit Inspection and Quarantine Bureau, Xiamen 361026, China.
authors.forename: Dunming
authors.initials: D
authors.lastname: Xu
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China. Electronic address: cyyang@xmu.edu.cn.
authors.forename: Chaoyong
authors.initials: C
authors.lastname: Yang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods; D021881:DNA, Catalytic / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D056656:Lab-On-A-Chip Devices; D060106:Lakes / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D014501:Uranium / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D021881:DNA, Catalytic; D006046:Gold; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D014501:Uranium; D014875:Water Pollutants, Radioactive; D000099166:Polyacrylamides
keywords: DNA hydrogel; DNAzyme; Portable detection; Uranium