title: Chromatic biosensor for detection of phosphinothricin acetyltransferase by use of polydiacetylene vesicles encapsulated within automatically generated immunohydrogel beads.
abstract: We developed a simple and sensitive colorimetric biosensor in the form of microparticles by using polydiacetylene (PDA) vesicles encapsulated within a hydrogel matrix for the detection of phosphinothricin acetyltransferase (PAT) protein, which is one of the most important marker proteins in genetically modified (GM) crops. Although PDA is commonly used as a sensing material due to its unique colorimetric properties, existing PDA biosensors are ineffective due to their low sensitivity as well as their lack of robustness. To overcome these disadvantages, we devised immunohydrogel beads made of anti-PAT-conjugated PDA vesicles embedded at high density within a poly(ethylene glycol) diacrylate (PEG-DA) hydrogel matrix. In addition, the construction of immunohydrogel beads was automated by use of a microfluidic device. In the immunoreaction, the sensitivity of antibody-conjugated PDA vesicles was significantly amplified, as monitored by the unaided eye. The limit of detection for target molecules reached as low as 20 nM, which is sufficiently low enough to detect target materials in GM organisms. Collectively, the results show that immunohydrogel beads constitute a promising colorimetric sensing platform for onsite testing in a number of fields, such as the food and medical industries, as well as warfare situations.
authors.affiliation: Department of Biological Engineering, ‡Biohybrid Systems Research Center, and ⊥Department of Mechanical Engineering, Inha University , Incheon 402-751, Korea.
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Jung
authors.forename: Huisoo
authors.initials: H
authors.lastname: Jang
authors.forename: Min-Cheol
authors.initials: MC
authors.lastname: Lim
authors.forename: Jae-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Kong-Sik
authors.initials: KS
authors.lastname: Shin
authors.forename: Sun Min
authors.initials: SM
authors.lastname: Kim
authors.forename: Hae-Yeong
authors.initials: HY
authors.lastname: Kim
authors.forename: Young-Rok
authors.initials: YR
authors.lastname: Kim
authors.forename: Tae-Joon
authors.initials: TJ
authors.lastname: Jeon
mesh_terms: D000123:Acetyltransferases / Q000032:analysis*; D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation; D003124:Colorimetry / Q000295:instrumentation; D018556:Crops, Agricultural / Q000201:enzymology*; D004867:Equipment Design; D030841:Food, Genetically Modified; D020100:Hydrogels / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation; D057230:Limit of Detection; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D000078789:Polyacetylene Polymer; D011108:Polymers / Q000737:chemistry*; D053279:Polyynes / Q000737:chemistry*
chemical_list: D055910:Antibodies, Immobilized; D020100:Hydrogels; D000078789:Polyacetylene Polymer; D011108:Polymers; D053279:Polyynes; C082361:polydiacetylene; D000123:Acetyltransferases; C056243:phosphinothricin N-acetyltransferase