title: Integration of target responsive hydrogel with cascaded enzymatic reactions and microfluidic paper-based analytic devices (µPADs) for point-of-care testing (POCT).
abstract: Paper based microfluidics (µPADs) with advantages of portability, low cost, and ease of use have attracted extensive attention. Here we describe a novel method that integrates glucoamylase-trapped aptamer-crosslinked hydrogel for molecular recognition with cascaded enzymatic reactions for signal amplification and a µPAD for portable readout. Upon target introduction, the hydrogel decomposes to release glucoamylase, which catalyzes the hydrolysis of amylose to produce a large amount of glucose. With a simple folding of the µPAD, the sample solution containing glucose product wicks and diffuses in parallel to each test-zone to carry out homogeneous assays, where glucose is used to produce I2 for brown color visualization through multiple enzymatic and chemical cascade reactions. Through color gradient changes based on different concentrations of the target, a semiquantitative assay is achieved by the naked eye, and quantitation can be obtained by handheld devices. Detection of cocaine in buffer and urine was performed to demonstrate the utility of the hydrogel-µPAD system. More importantly, the hydrogel-µPAD system can be extended to the detection of various targets by incorporating the corresponding aptamer into the hydrogel. The hydrogel-µPAD system reported here provides a new platform for portable, disposable and visual detection of a wide range of targets.
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis and 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: Tian
authors.initials: T
authors.lastname: Tian
authors.affiliation: MOE Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wei
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis and 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: Shasha
authors.initials: S
authors.lastname: Jia
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis and 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: Ruihua
authors.initials: R
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis and 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: Jiuxing
authors.initials: J
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis and 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 and 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: Huimin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis and 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 Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Lin
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis and 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 James
authors.initials: CJ
authors.lastname: Yang
mesh_terms: D003042:Cocaine / Q000097:blood* / Q000652:urine*; D003124:Colorimetry / Q000295:instrumentation; D004209:Disposable Equipment; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry; D056656:Lab-On-A-Chip Devices; D010209:Paper; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000295:instrumentation
chemical_list: D020100:Hydrogels; D005087:Glucan 1,4-alpha-Glucosidase; D003042:Cocaine
keywords: Aptamer; Cascaded enzymatic reactions; Hydrogel; Point-of-care; µPAD