Abstract
In this paper we report the development of an ultrasensitive photonic sensor based on nanoporous silicon (NPS) substrate for heavy metal ions detection in a FTIR reflection system. A one-dimensional photonic crystal with disturbed Bragg reflector (DBR) fabricated by successive electrochemical etchings (ECE) is employed to enhance the reflected IR signals [1] [2]. This well-defined NPS nanostructures will be red shifted due to the increase in the refractive index of the Fe 3+ ion solution (1 mM). The Fe 3+ with difference concentration due to difference spectrum shift, and the average sensitivity is 22.3cm -1 /mM corresponding to a detection limit of 10.8 ppm.