| 초록 |
We developed a simple and sensitive colorimetric biosensor in the form of a micro-particle by using polydiacetylene (PDA) vesicles encapsulated within a hydrogel matrix to detect phosphinothricin acetyltransferase (PAT) protein which is one of the most important marker proteins in genetically modified(GM) crops. PDA is commonly used as a sensing material due to its unique feature. PDA changes its color upon external stimuli such as pH, temperature, and mechanical and physical stresses. However, existing biosensors with PDA are less effective in terms of their low sensitivity and signal ratio to target materials, as well as their lack of robustness. To overcome those disadvantages, we devised immuno-hydrogel beads in which PDA vesicles are embedded with high density in a poly(ethylene glycol) diacrylate (PEG-DA) hydrogel matrix. As a result of immunoreaction, a degree of the color change-blue to red- of antibody conjugated PDA vesicles was significantly amplified. In addition, color changes can be monitored with the unaided eye or simple RGB analysis. The detection limit of this system to the target molecules reached as low as 20 nM, which is far sufficient for the detection of marker proteins in the GM crops. All the results show immuno-hydrogel beads will be promising colorimetric sensing platforms for onsite testing, and be useful for the diagnoses and detection of biological analytes in a number of fields, such as food, medical, and pharmaceutical industry. |
