Features: Bisphenol A may be released from many kinds of plastic container products. It causes detrimental effects on brain and hormone development in …
Bisphenol A may be released from many kinds of plastic container products. It causes detrimental effects on brain and hormone development in complex ways and it interferes with metabolism, even at low concentrations. Therefore, an advanced technology which can quickly and accurately monitor this and other such compounds is in high demand.
ITRI developed an inverse opal photonic crystal, which is prepared using a periodical assembly of microspheres in 3-D as the template. The template is dipped or filled with an imprinted solution containing BPA, cross-linkers and functional monomers. After gelation of this solution, the microspheres and BPA are removed by solvent washing to generate the photonic crystal structure with BPA imprinted material in the skeleton.
The molecular imprinted material offers highly accurate identification and is not easily interfered with by other matrices. It can be applied in detecting BPA.
The detection of BPA is conducted simply by putting the photonic crystal detector in a solution sample. Any BPA in the sample is absorbed by BPA molecular imprinted nanocavities on the photonic crystal sensor, causing changes in the sensor’s reflective index which can be observed as a shift.
The BPA concentrations can be determined by the Bragg shifts of the photonic crystal detector. It has the following advantages:
1. Detects concentrations of bisphenol A as low as 10µg/L, with a standard deviation lower than 20%.
2. Bisphenol A in a solution sample can be detected in less than ten minutes, and the photonic crystal detector can be reused up to 5 times.
3. The photonic crystal detector apparatus is small and portable.
4. Integrated chips can be developed to simultaneously detect a variety of environmental pollutants.
Further development of molecularly imprinted photonic crystals will enable easy and inexpensive monitoring of a variety of environmental hormones. By adding different molecularly imprinted designs to the photonic crystal template, different target pollutants can be analyzed simultaneously. This technology greatly reduces analytic costs and improves efficiency as well.