Detection of o-Phthalaldehyde by Two-dimensional Photonic Crystal Hydrogel Sensor
o-Phthalaldehyde(OPA)is a new type of chemical disinfectant widely used in medical institutions.The development of new efficient and convenient detection platforms or methods for OPA is of great significance.In this work,in two-dimensional photonic crystal(2DPC)hydrogel,a responsive 2DPC hydrogel was prepared by functionalizing the hydrogel with ethylenediamine(EDA)and embedding amino groups.The amino group on the polymer chain of 2DPC hydrogel reacted with OPA,and with the increase of OPA concentration,the crosslinking density of the hydrogel also increased,resulting in the volume phase transition of the hydrogel,e.g.,shrinkage phenomenon.In the meantime,the spacing of 2DPC microspheres gradually decreased,while the diameter of Debye diffraction ring gradually increased.The results showed that the change of particle size spacing had a good linear relationship with logarithm of concentration of OPA in the range of 101‒106 nmol/L,with the detection limit of 0.21 nmol/L(3σ/k).Therefore,the amino functionalized photonic crystal hydrogel sensor could realize the quantitative detection of OPA.The method was simple with low cost,ease to operate and use.Then the practicability of this hydrogel sensor for real sample was verified in the diluted clinical disinfectant.The recoveries of OPA in the diluted disinfectant were 100%‒103%,with a relative standard deviations of 1.8%‒5.5%.The results proved that 2DPC hydrogel sensor could be used for detection of OPA in disinfectant used for clinical endoscopes and other instruments.