| We developed a prototype of polyacrylamide (PAAm) -based sensor platform which can be used to detect chemical- and bio- agent with low-cost, easy-to-use, fast screening, and in-site detecting tool. By changing the cross-linker of the hydrogel, various agents can be detected. We firstly integrated the hydrogel into a microchannel, and developed a BoNT sensor based on the morphology change of this hydrogel. The hydrogel in the microchannel can be degraded in 22 h at 45 mug/mL of light chain (LC) of botulinum toxin type A (BoNT/A) and 90 h at the lowest concentration of 4.5 mug/mL of LC. To improve the sensitivity and testing time of the hydrogel-based bio-toxin sensors, we introduce an optical fiber Fabry Perot interferometer (FPI) to detect the changes in the optical properties induced by the reactions between the target agent and the hydrogel. Compared to our previous hydrogel-based sensor based on the microscopy observation, the sensitivity of the optic fiber FPI is improved by 2000 times, and testing time is shortened from tens of hours to a few hours. In order to further enhance the sensitivity and detection speed, we combined the fiber optics with microfluidics. The preliminary study of the combination showed that the LC of 4.5 mug/ml was detected in 24 hours, while the previous detection time was about 90 hours. Due to the combination, the detection speed was further increased by 4 times. Our approach opens up an avenue for highly-sensitive, high-speed in-field detection of bio-toxins in live samples. |
PDF Full Text Request