Facile microwave-assisted synthesis of agarose hydrogel for fibre optic biosensors application

Hydrogels are networks of polymer which are highly swollen with the water molecule. One of the known great renewable resources that can be possessed from the life cycle of animals and plants is biopolymers. A facile synthesis method on the formation of biopolymer called agarose for fibre optic sensing purpose has been investigated by comparing the synthesis method of agarose with and without a microwave-assisted (MA). UV-visible spectroscopy measurement was conducted for both transmission and absorbance mode to investigate the transparency of the crosslinked hydrogel prior deposited onto the fibre optic probe. As a result, the highest transparency hydrogel was obtained from the polymer precursor prepared with the MA method. Scanning Electron Microscopy (SEM) characterisation was used to confirm the coated agarose hydrogel onto the exposed fibre optic core. The coating of agarose hydrogel onto fibre optic probe was done at different dipping time, which was at 1, 3 and 5 minutes; respectively. It can be seen the coverage and thickness of the agarose hydrogel gradually increase as the dipping time increases. The 5 minutes dipped fibre optic probe has shown an increment of 2.07% in thickness compared to the uncoated probe and resulted in the smoothest coated surface, thus promising to be used as a sensor platform for the sensing application.