title: Sensitive inkjet printing paper-based colormetric strips for acetylcholinesterase inhibitors with indoxyl acetate substrate.
abstract: A new paper-based biosensing approach has been developed for sensitive and rapid detection of acetylcholinesterase (AChE) inhibitors. The biosensing zone of the paper strip is constructed with an inkjet printing method, and the biomolecule AChE is immobilized into two layers of biocompatible sol-gel-derived silica ink with a "sandwich" form. Indoxyl acetate (IDA) is used as a chromogenic substrate, which is colorless and can be catalytically hydrolyzed into blue-colored indigo dipolymer. When the enzymatic activity of AChE is inhibited after incubation with organophosphate pesticides (OPs), there is a decreased hydrolysis of IDA accompanying with a drop in color intensity. Paraoxon and trichlorfon are used as the representative OPs in the assay. Due to the low solubility and high molar absorption coefficient of the IDA dipolymer product, the paper-based strip can form a neat blue sensing zone and shows obviously improved sensitivity with a limit of detection (LOD) of 0.01ngmL-1paraoxon and 0.04ngmL-1trichlorfon (S/N=3) and the LODs for visual detection are 0.03ngmL-1for paraoxon and 0.1ngmL-1for trichlorfon comparing with the previously reported colorimetric methods. The concentrations of paraoxon in apple juice samples are also detected, and the results are in accord well with these results from high-performance liquid chromatography, showing great potential for on-site detection of OPs in practical application. The developed assay can be used to qualitatively and semiquantitatively estimate with naked eyes and quantitatively assess OPs through image analysis.
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Yongfang
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Fubing
authors.initials: F
authors.lastname: Xiao
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China. Electronic address: zywu@hnu.edu.cn.
authors.forename: Zhaoyang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Ruqin
authors.initials: R
authors.lastname: Yu
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000378:metabolism*; D002863:Chromogenic Compounds / Q000737:chemistry / Q000378:metabolism*; D003124:Colorimetry / Q000295:instrumentation / Q000379:methods*; D007211:Indoles / Q000737:chemistry / Q000378:metabolism*; D007281:Ink; D008956:Models, Chemical; D015394:Molecular Structure; D010209:Paper; D010261:Paraoxon / Q000737:chemistry / Q000378:metabolism; D011327:Printing; D015203:Reproducibility of Results; D014236:Trichlorfon / Q000737:chemistry / Q000378:metabolism
chemical_list: D002800:Cholinesterase Inhibitors; D002863:Chromogenic Compounds; D007211:Indoles; C053640:indoxyl acetate; D014236:Trichlorfon; D000110:Acetylcholinesterase; D010261:Paraoxon
keywords: Acetylcholinesterase; Indoxyl acetate; Inkjet printing; Organophosphate pesticides; Paper-based strip